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diff --git a/hidden_order.bib b/hidden_order.bib index 501b56c..ebdf4ca 100644 --- a/hidden_order.bib +++ b/hidden_order.bib @@ -1,4 +1,47 @@ +@book{landau_theory_1995, + series = {Landau and {{Lifshitz Course}} of {{Theoretical Physics}}}, + title = {Theory of {{Elasticity}}}, + author = {Landau, Lev Davidovich and Lifshitz, Eugin M and Berestetskii, VB and Pitaevskii, LP}, + year = {1995}, + keywords = {_tablet}, + file = {/home/pants/.zotero/storage/AQ7G8AHB/Landau et al. - 1995 - Theory of Elasticity.pdf} +} + +@article{ginzburg_remarks_1961, + title = {Some {{Remarks}} on {{Phase Transitions}} of the {{Second Kind}} and the {{Microscopic}} Theory of {{Ferroelectric Materials}}}, + volume = {2}, + number = {9}, + journal = {Soviet Physics, Solid State}, + author = {Ginzburg, V. L.}, + year = {1961}, + keywords = {⛔ No DOI found}, + pages = {1824-1834}, + file = {/home/pants/.zotero/storage/JVMTIZGB/Ginzburg - 1961 - Some Remarks on Phase Transitions of the Second Ki.pdf} +} + +@article{lifshitz_theory_1942, + title = {On the Theory of Phase Transitions of the Second Order {{I}}. {{Changes}} of the Elementary Cell of a Crystal in Phase Transitions of the Second Order}, + volume = {6}, + journal = {Proceedings of the USSR Academy of Sciences Journal of Physics}, + author = {Lifshitz, EM}, + year = {1942}, + keywords = {_tablet,⛔ No DOI found}, + pages = {61}, + file = {/home/pants/.zotero/storage/D9BYG3FK/Lifshitz - 1942 - On the theory of phase transitions of the second o.pdf} +} + +@article{lifshitz_theory_1942-1, + title = {On the Theory of Phase Transitions of the Second Order {{II}}. {{Phase}} Transitions of the Second Order in Alloys}, + volume = {6}, + journal = {Proceedings of the USSR Academy of Sciences Journal of Physics}, + author = {Lifshitz, EM}, + year = {1942}, + keywords = {_tablet,⛔ No DOI found}, + pages = {251}, + file = {/home/pants/.zotero/storage/TAA9G46H/Lifshitz - 1942 - On the theory of phase transitions of the second o.pdf} +} + @article{el-showk_solving_2014, title = {Solving the 3d {{Ising Model}} with the {{Conformal Bootstrap II}}. {$\mathsl{c}$}-{{Minimization}} and {{Preise Critial Exponents}}}, volume = {157}, @@ -13,32 +56,7 @@ year = {2014}, keywords = {_tablet}, pages = {869-914}, - file = {/home/pants/.zotero/data/storage/XB5EWQ28/El-Showk et al. - 2014 - Solving the 3d Ising Model with the Conformal Boot.pdf} -} - -@article{guida_critical_1998, - title = {Critical Exponents of the {{N}}-Vector Model}, - volume = {31}, - issn = {0305-4470}, - abstract = {Recently the series for two renormalization group functions (corresponding to the anomalous dimensions of the fields \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img1.gif] and \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img2.gif] ) of the three-dimensional \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img3.gif] field theory have been extended to next order (seven loops) by Murray and Nickel. We examine the influence of these additional terms on the estimates of critical exponents of the N -vector model, using some new ideas in the context of the Borel summation techniques. The estimates have slightly changed, but remain within the errors of the previous evaluation. Exponents such as \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img4.gif] (related to the field anomalous dimension), which were poorly determined in the previous evaluation of Le Guillou-Zinn-Justin, have seen their apparent errors significantly decrease. More importantly, perhaps, summation errors are better determined. The change in exponents affects the recently determined ratios of amplitudes and we report the corresponding new values. Finally, because an error has been discovered in the last order of the published \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img5.gif] expansions (order \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img6.gif] ), we have also re-analysed the determination of exponents from the \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img7.gif] -expansion. The conclusion is that the general agreement between \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img7.gif] -expansion and three-dimensional series has improved with respect to Le Guillou-Zinn-Justin.}, - language = {en}, - number = {40}, - journal = {Journal of Physics A: Mathematical and General}, - doi = {10.1088/0305-4470/31/40/006}, - author = {Guida, R. and {Zinn-Justin}, J.}, - year = {1998}, - keywords = {_tablet}, - pages = {8103}, - file = {/home/pants/.zotero/data/storage/K468APXL/Guida and Zinn-Justin - 1998 - Critical exponents of the N-vector model.pdf} -} - -@book{landau_theory_1995, - series = {Landau and {{Lifshitz Course}} of {{Theoretical Physics}}}, - title = {Theory of {{Elasticity}}}, - author = {Landau, Lev Davidovich and Lifshitz, Eugin M and Berestetskii, VB and Pitaevskii, LP}, - year = {1995}, - keywords = {_tablet}, - file = {/home/pants/.zotero/data/storage/AQ7G8AHB/Landau et al. - 1995 - Theory of Elasticity.pdf} + file = {/home/pants/.zotero/storage/XB5EWQ28/El-Showk et al. - 2014 - Solving the 3d Ising Model with the Conformal Boot.pdf} } @article{fisher_specific_1990, @@ -55,7 +73,7 @@ year = {1990}, keywords = {_tablet}, pages = {419-423}, - file = {/home/pants/.zotero/data/storage/HHVDKMSP/Fisher et al. - 1990 - Specific heat of URu₂Si₂ Effect of pressure and m.pdf} + file = {/home/pants/.zotero/storage/HHVDKMSP/Fisher et al. - 1990 - Specific heat of URu₂Si₂ Effect of pressure and m.pdf} } @article{hornreich_lifshitz_1980, @@ -71,70 +89,67 @@ year = {1980}, keywords = {_tablet}, pages = {387-392}, - file = {/home/pants/.zotero/data/storage/FQWHY9TF/Hornreich - 1980 - The Lifshitz point Phase diagrams and critical be.pdf} + file = {/home/pants/.zotero/storage/FQWHY9TF/Hornreich - 1980 - The Lifshitz point Phase diagrams and critical be.pdf} } -@article{lifshitz_theory_1942-1, - title = {On the Theory of Phase Transitions of the Second Order {{II}}. {{Phase}} Transitions of the Second Order in Alloys}, - volume = {6}, - journal = {Proceedings of the USSR Academy of Sciences Journal of Physics}, - author = {Lifshitz, EM}, - year = {1942}, - keywords = {⛔ No DOI found,_tablet}, - pages = {251}, - file = {/home/pants/.zotero/data/storage/TAA9G46H/Lifshitz - 1942 - On the theory of phase transitions of the second o.pdf} -} - -@article{lifshitz_theory_1942, - title = {On the Theory of Phase Transitions of the Second Order {{I}}. {{Changes}} of the Elementary Cell of a Crystal in Phase Transitions of the Second Order}, - volume = {6}, - journal = {Proceedings of the USSR Academy of Sciences Journal of Physics}, - author = {Lifshitz, EM}, - year = {1942}, - keywords = {⛔ No DOI found,_tablet}, - pages = {61}, - file = {/home/pants/.zotero/data/storage/D9BYG3FK/Lifshitz - 1942 - On the theory of phase transitions of the second o.pdf} +@article{guida_critical_1998, + title = {Critical Exponents of the {{N}}-Vector Model}, + volume = {31}, + issn = {0305-4470}, + abstract = {Recently the series for two renormalization group functions (corresponding to the anomalous dimensions of the fields \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img1.gif] and \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img2.gif] ) of the three-dimensional \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img3.gif] field theory have been extended to next order (seven loops) by Murray and Nickel. We examine the influence of these additional terms on the estimates of critical exponents of the N -vector model, using some new ideas in the context of the Borel summation techniques. The estimates have slightly changed, but remain within the errors of the previous evaluation. Exponents such as \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img4.gif] (related to the field anomalous dimension), which were poorly determined in the previous evaluation of Le Guillou-Zinn-Justin, have seen their apparent errors significantly decrease. More importantly, perhaps, summation errors are better determined. The change in exponents affects the recently determined ratios of amplitudes and we report the corresponding new values. Finally, because an error has been discovered in the last order of the published \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img5.gif] expansions (order \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img6.gif] ), we have also re-analysed the determination of exponents from the \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img7.gif] -expansion. The conclusion is that the general agreement between \#\#IMG\#\# [http://ej.iop.org/images/0305-4470/31/40/006/img7.gif] -expansion and three-dimensional series has improved with respect to Le Guillou-Zinn-Justin.}, + language = {en}, + number = {40}, + journal = {Journal of Physics A: Mathematical and General}, + doi = {10.1088/0305-4470/31/40/006}, + author = {Guida, R. and {Zinn-Justin}, J.}, + year = {1998}, + keywords = {_tablet}, + pages = {8103}, + file = {/home/pants/.zotero/storage/K468APXL/Guida and Zinn-Justin - 1998 - Critical exponents of the N-vector model.pdf} } -@article{ginzburg_remarks_1961, - title = {Some {{Remarks}} on {{Phase Transitions}} of the {{Second Kind}} and the {{Microscopic}} Theory of {{Ferroelectric Materials}}}, +@article{varshni_temperature_1970, + title = {Temperature {{Dependence}} of the {{Elastic Constants}}}, volume = {2}, - number = {9}, - journal = {Soviet Physics, Solid State}, - author = {Ginzburg, V. L.}, - year = {1961}, - keywords = {⛔ No DOI found}, - pages = {1824-1834}, - file = {/home/pants/.zotero/data/storage/JVMTIZGB/Ginzburg - 1961 - Some Remarks on Phase Transitions of the Second Ki.pdf} + abstract = {The following two equations are proposed for the temperature dependence of the elastic stiffness constants: cij=c0ij-s(etT-1) and cij=a-bT2(T+c), where c0ij, s, t, a, b, and c are constants. The applicability of these two equations and that of Wachtman's equation is examined for 57 elastic constants of 22 substances. The first equation has a theoretical justification and gives the best over-all results. Neither of the three equations give the theoretically expected T4 dependence at low temperatures, and therefore they are not expected to give very accurate results at very low temperatures ({$\lessequivlnt\Theta$}D50). A new melting criterion is also examined.}, + number = {10}, + journal = {Physical Review B}, + doi = {10.1103/physrevb.2.3952}, + author = {Varshni, Y. P.}, + month = nov, + year = {1970}, + pages = {3952-3958}, + file = {/home/pants/.zotero/storage/QN7TLJV7/Varshni - 1970 - Temperature Dependence of the Elastic Constants.pdf} } -@article{choi_pressure-induced_2018, - title = {Pressure-Induced Rotational Symmetry Breaking in \$\{\textbackslash{}mathrm\{\vphantom{\}\}}{{URu}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$}, - volume = {98}, - abstract = {Phase transitions and symmetry are intimately linked. Melting of ice, for example, restores translation invariance. The mysterious hidden order (HO) phase of URu2Si2 has, despite relentless research efforts, kept its symmetry breaking element intangible. Here, we present a high-resolution x-ray diffraction study of the URu2Si2 crystal structure as a function of hydrostatic pressure. Below a critical pressure threshold pc{$\approx$}3 kbar, no tetragonal lattice symmetry breaking is observed even below the HO transition THO=17.5 K. For p{$>$}pc, however, a pressure-induced rotational symmetry breaking is identified with an onset temperatures TOR{$\sim$}100 K. The emergence of an orthorhombic phase is found and discussed in terms of an electronic nematic order that appears unrelated to the HO, but with possible relevance for the pressure-induced antiferromagnetic (AF) phase. Existing theories describe the HO and AF phases through an adiabatic continuity of a complex order parameter. Since none of these theories predicts a pressure-induced nematic order, our finding adds an additional symmetry breaking element to this long-standing problem.}, - number = {24}, +@article{kiss_group_2005, + title = {Group Theory and Octupolar Order in \$\textbackslash{}mathrm\{\vphantom\}{{U}}\vphantom\{\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Ru}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$}, + volume = {71}, + abstract = {Recent experiments on URu2Si2URu2Si2 show that the low-pressure hidden order is nonmagnetic but it breaks time reversal invariance. Restricting our attention to local order parameters of 5f25f2 shells, we find that the best candidate for hidden order is staggered order of either Tz{$\beta$}T{$\beta$}z or TxyzTxyz octupoles. Group theoretical arguments for the effect of symmetry-lowering perturbations (magnetic field, mechanical stress) predict behavior in good overall agreement with observations. We illustrate our general arguments on the example of a five-state crystal field model which differs in several details from models discussed in the literature. The general appearance of the mean field phase diagram agrees with the experimental results. In particular, we find that (a) at zero magnetic field, there is a first-order phase boundary between octupolar order and large-moment antiferromagnetism with increasing hydrostatic pressure; (b) arbitrarily weak uniaxial pressure induces staggered magnetic moments in the octupolar phase; and (c) a new phase with different symmetry appears at large magnetic fields.}, + number = {5}, journal = {Physical Review B}, - doi = {10/gf5c39}, - author = {Choi, J. and Ivashko, O. and Dennler, N. and Aoki, D. and {von Arx}, K. and Gerber, S. and Gutowski, O. and Fischer, M. H. and Strempfer, J. and {v. Zimmermann}, M. and Chang, J.}, - month = dec, - year = {2018}, - pages = {241113}, - file = {/home/pants/.zotero/data/storage/8IBGVH7U/Choi et al. - 2018 - Pressure-induced rotational symmetry breaking in $.pdf} + doi = {10.1103/physrevb.71.054415}, + author = {Kiss, Annam{\'a}ria and Fazekas, Patrik}, + month = feb, + year = {2005}, + pages = {054415}, + file = {/home/pants/.zotero/storage/YTARVDIM/Kiss and Fazekas - 2005 - Group theory and octupolar order in $mathrm U m.pdf} } -@article{hassinger_temperature-pressure_2008, - title = {Temperature-Pressure Phase Diagram of \$\textbackslash{}mathrm\{\vphantom\}{{U}}\vphantom\{\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Ru}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$ from Resistivity Measurements and Ac Calorimetry: {{Hidden}} Order and {{Fermi}}-Surface Nesting}, - volume = {77}, - shorttitle = {Temperature-Pressure Phase Diagram of \$\textbackslash{}mathrm\{\vphantom\}{{U}}\vphantom\{\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Ru}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$ from Resistivity Measurements and Ac Calorimetry}, - abstract = {By performing combined resistivity and calorimetric experiments under pressure, we have determined a precise temperature-pressure (T,P) phase diagram of the heavy fermion compound URu2Si2. It will be compared with previous diagrams determined by elastic neutron diffraction and strain gauge techniques. At first glance, the low-pressure ordered phase referred to as hidden order is dominated by Fermi-surface nesting, which has strong consequences on the localized spin dynamics. The high-pressure phase is dominated by large moment antiferromagnetism (LMAF) coexisting with at least dynamical nesting needed to restore on cooling a local moment behavior. ac calorimetry confirms unambiguously that bulk superconductivity does not coexist with LMAF. URu2Si2 is one of the most spectacular examples of the dual itinerant and local character of uranium-based heavy fermion compounds.}, +@article{haule_arrested_2009, + title = {Arrested {{Kondo}} Effect and Hidden Order in {{URu}}{\textsubscript{2}}{{Si}}{\textsubscript{2}}}, + volume = {5}, + issn = {1745-2481}, + abstract = {Complex electronic matter shows subtle forms of self-organization, which are almost invisible to the available experimental tools. One prominent example is provided by the heavy-fermion material URu2Si2. At high temperature, the 5f electrons of uranium carry a very large entropy. This entropy is released at 17.5 K by means of a second-order phase transition1 to a state that remains shrouded in mystery, termed a `hidden order' state2. Here, we develop a first-principles theoretical method to analyse the electronic spectrum of correlated materials as a function of the position inside the unit cell of the crystal and use it to identify the low-energy excitations of URu2Si2. We identify the order parameter of the hidden-order state and show that it is intimately connected to magnetism. Below 70 K, the 5f electrons undergo a multichannel Kondo effect, which is `arrested' at low temperature by the crystal-field splitting. At lower temperatures, two broken-symmetry states emerge, characterized by a complex order parameter {$\psi$}. A real {$\psi$} describes the hidden-order phase and an imaginary {$\psi$} corresponds to the large-moment antiferromagnetic phase. Together, they provide a unified picture of the two broken-symmetry phases in this material.}, + language = {en}, number = {11}, - journal = {Physical Review B}, - doi = {10.1103/physrevb.77.115117}, - author = {Hassinger, E. and Knebel, G. and Izawa, K. and Lejay, P. and Salce, B. and Flouquet, J.}, - month = mar, - year = {2008}, - pages = {115117}, - file = {/home/pants/.zotero/data/storage/U5V8JT6U/Hassinger et al. - 2008 - Temperature-pressure phase diagram of $mathrm U .pdf} + journal = {Nature Physics}, + doi = {10/fw2wcx}, + author = {Haule, Kristjan and Kotliar, Gabriel}, + month = nov, + year = {2009}, + pages = {796-799}, + file = {/home/pants/.zotero/storage/L3WFEVLT/Haule and Kotliar - 2009 - Arrested Kondo effect and hidden order in URusub.pdf} } @article{kambe_odd-parity_2018, @@ -149,23 +164,7 @@ month = jun, year = {2018}, pages = {235142}, - file = {/home/pants/.zotero/data/storage/UQWWD3SU/Kambe et al. - 2018 - Odd-parity electronic multipolar ordering in $ ma.pdf} -} - -@article{haule_arrested_2009, - title = {Arrested {{Kondo}} Effect and Hidden Order in {{URu}}{\textsubscript{2}}{{Si}}{\textsubscript{2}}}, - volume = {5}, - issn = {1745-2481}, - abstract = {Complex electronic matter shows subtle forms of self-organization, which are almost invisible to the available experimental tools. One prominent example is provided by the heavy-fermion material URu2Si2. At high temperature, the 5f electrons of uranium carry a very large entropy. This entropy is released at 17.5 K by means of a second-order phase transition1 to a state that remains shrouded in mystery, termed a `hidden order' state2. Here, we develop a first-principles theoretical method to analyse the electronic spectrum of correlated materials as a function of the position inside the unit cell of the crystal and use it to identify the low-energy excitations of URu2Si2. We identify the order parameter of the hidden-order state and show that it is intimately connected to magnetism. Below 70 K, the 5f electrons undergo a multichannel Kondo effect, which is `arrested' at low temperature by the crystal-field splitting. At lower temperatures, two broken-symmetry states emerge, characterized by a complex order parameter {$\psi$}. A real {$\psi$} describes the hidden-order phase and an imaginary {$\psi$} corresponds to the large-moment antiferromagnetic phase. Together, they provide a unified picture of the two broken-symmetry phases in this material.}, - language = {en}, - number = {11}, - journal = {Nature Physics}, - doi = {10/fw2wcx}, - author = {Haule, Kristjan and Kotliar, Gabriel}, - month = nov, - year = {2009}, - pages = {796-799}, - file = {/home/pants/.zotero/data/storage/L3WFEVLT/Haule and Kotliar - 2009 - Arrested Kondo effect and hidden order in URusub.pdf} + file = {/home/pants/.zotero/storage/UQWWD3SU/Kambe et al. - 2018 - Odd-parity electronic multipolar ordering in $ ma.pdf} } @article{kusunose_hidden_2011, @@ -180,7 +179,7 @@ month = jul, year = {2011}, pages = {084702}, - file = {/home/pants/.zotero/data/storage/VSG5VAMT/Kusunose and Harima - 2011 - On the Hidden Order in URu2Si2 – Antiferro Hexadec.pdf} + file = {/home/pants/.zotero/storage/VSG5VAMT/Kusunose and Harima - 2011 - On the Hidden Order in URu2Si2 – Antiferro Hexadec.pdf} } @article{kung_chirality_2015, @@ -202,24 +201,10 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = mar, year = {2015}, pages = {1339-1342}, - file = {/home/pants/.zotero/data/storage/E93SDWTG/Kung et al. - 2015 - Chirality density wave of the “hidden order” phase.pdf}, + file = {/home/pants/.zotero/storage/E93SDWTG/Kung et al. - 2015 - Chirality density wave of the “hidden order” phase.pdf}, pmid = {25678557} } -@article{cricchio_itinerant_2009, - title = {Itinerant {{Magnetic Multipole Moments}} of {{Rank Five}} as the {{Hidden Order}} in \$\{\textbackslash{}mathrm\{\vphantom{\}\}}{{URu}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$}, - volume = {103}, - abstract = {A broken symmetry ground state without any magnetic moments has been calculated by means of the local-density approximation to density functional theory plus a local exchange term, the so-called LDA+U approach, for URu2Si2. The solution is analyzed in terms of a multipole tensor expansion of the itinerant density matrix and is found to be a nontrivial magnetic multipole. Analysis and further calculations show that this type of multipole enters naturally in time reversal breaking in the presence of large effective spin-orbit coupling and coexists with magnetic moments for most magnetic actinides.}, - number = {10}, - journal = {Physical Review Letters}, - doi = {10/csgzd4}, - author = {Cricchio, Francesco and Bultmark, Fredrik and Gr{\aa}n{\"a}s, Oscar and Nordstr{\"o}m, Lars}, - month = sep, - year = {2009}, - pages = {107202}, - file = {/home/pants/.zotero/data/storage/KAXQ32EJ/Cricchio et al. - 2009 - Itinerant Magnetic Multipole Moments of Rank Five .pdf} -} - @article{ohkawa_quadrupole_1999, title = {Quadrupole and Dipole Orders in {{URu2Si2}}}, volume = {11}, @@ -233,7 +218,21 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = nov, year = {1999}, pages = {L519--L524}, - file = {/home/pants/.zotero/data/storage/AG7SQ5WT/Ohkawa and Shimizu - 1999 - Quadrupole and dipole orders in URu2Si2.pdf} + file = {/home/pants/.zotero/storage/AG7SQ5WT/Ohkawa and Shimizu - 1999 - Quadrupole and dipole orders in URu2Si2.pdf} +} + +@article{cricchio_itinerant_2009, + title = {Itinerant {{Magnetic Multipole Moments}} of {{Rank Five}} as the {{Hidden Order}} in \$\{\textbackslash{}mathrm\{\vphantom{\}\}}{{URu}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$}, + volume = {103}, + abstract = {A broken symmetry ground state without any magnetic moments has been calculated by means of the local-density approximation to density functional theory plus a local exchange term, the so-called LDA+U approach, for URu2Si2. The solution is analyzed in terms of a multipole tensor expansion of the itinerant density matrix and is found to be a nontrivial magnetic multipole. Analysis and further calculations show that this type of multipole enters naturally in time reversal breaking in the presence of large effective spin-orbit coupling and coexists with magnetic moments for most magnetic actinides.}, + number = {10}, + journal = {Physical Review Letters}, + doi = {10/csgzd4}, + author = {Cricchio, Francesco and Bultmark, Fredrik and Gr{\aa}n{\"a}s, Oscar and Nordstr{\"o}m, Lars}, + month = sep, + year = {2009}, + pages = {107202}, + file = {/home/pants/.zotero/storage/KAXQ32EJ/Cricchio et al. - 2009 - Itinerant Magnetic Multipole Moments of Rank Five .pdf} } @article{santini_crystal_1994, @@ -247,7 +246,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = aug, year = {1994}, pages = {1027-1030}, - file = {/home/pants/.zotero/data/storage/2ZPUF4NZ/Santini and Amoretti - 1994 - Crystal Field Model of the Magnetic Properties of .pdf} + file = {/home/pants/.zotero/storage/2ZPUF4NZ/Santini and Amoretti - 1994 - Crystal Field Model of the Magnetic Properties of .pdf} } @article{harima_why_2010, @@ -262,7 +261,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = mar, year = {2010}, pages = {033705}, - file = {/home/pants/.zotero/data/storage/2MY7VK9P/Harima et al. - 2010 - Why the Hidden Order in URu2Si2 Is Still Hidden–On.pdf} + file = {/home/pants/.zotero/storage/2MY7VK9P/Harima et al. - 2010 - Why the Hidden Order in URu2Si2 Is Still Hidden–On.pdf} } @article{thalmeier_signatures_2011, @@ -276,7 +275,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = apr, year = {2011}, pages = {165110}, - file = {/home/pants/.zotero/data/storage/UD5E2IUD/Thalmeier and Takimoto - 2011 - Signatures of hidden-order symmetry in torque osci.pdf} + file = {/home/pants/.zotero/storage/UD5E2IUD/Thalmeier and Takimoto - 2011 - Signatures of hidden-order symmetry in torque osci.pdf} } @article{tonegawa_cyclotron_2012, @@ -290,7 +289,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = jul, year = {2012}, pages = {036401}, - file = {/home/pants/.zotero/data/storage/MHBZ6QTK/Tonegawa et al. - 2012 - Cyclotron Resonance in the Hidden-Order Phase of $.pdf} + file = {/home/pants/.zotero/storage/MHBZ6QTK/Tonegawa et al. - 2012 - Cyclotron Resonance in the Hidden-Order Phase of $.pdf} } @article{rau_hidden_2012, @@ -304,7 +303,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = jun, year = {2012}, pages = {245112}, - file = {/home/pants/.zotero/data/storage/6HP8DPHU/Rau and Kee - 2012 - Hidden and antiferromagnetic order as a rank-5 sup.pdf} + file = {/home/pants/.zotero/storage/6HP8DPHU/Rau and Kee - 2012 - Hidden and antiferromagnetic order as a rank-5 sup.pdf} } @article{riggs_evidence_2015, @@ -319,7 +318,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = mar, year = {2015}, pages = {6425}, - file = {/home/pants/.zotero/data/storage/Z57IE8J9/Riggs et al. - 2015 - Evidence for a nematic component to the hidden-ord.pdf} + file = {/home/pants/.zotero/storage/Z57IE8J9/Riggs et al. - 2015 - Evidence for a nematic component to the hidden-ord.pdf} } @article{hoshino_resolution_2013, @@ -334,7 +333,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = mar, year = {2013}, pages = {044707}, - file = {/home/pants/.zotero/data/storage/TY637XGC/Hoshino et al. - 2013 - Resolution of Entropy (lnsqrt 2 ) by Ordering .pdf} + file = {/home/pants/.zotero/storage/TY637XGC/Hoshino et al. - 2013 - Resolution of Entropy (lnsqrt 2 ) by Ordering .pdf} } @article{ikeda_theory_1998, @@ -349,7 +348,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = oct, year = {1998}, pages = {3723-3726}, - file = {/home/pants/.zotero/data/storage/QNE8NK4Q/Ikeda and Ohashi - 1998 - Theory of Unconventional Spin Density Wave A Poss.pdf} + file = {/home/pants/.zotero/storage/QNE8NK4Q/Ikeda and Ohashi - 1998 - Theory of Unconventional Spin Density Wave A Poss.pdf} } @article{chandra_hastatic_2013, @@ -365,7 +364,7 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = jan, year = {2013}, pages = {621-626}, - file = {/home/pants/.zotero/data/storage/B272KFL9/Chandra et al. - 2013 - Hastatic order in the heavy-fermion compound URus.pdf} + file = {/home/pants/.zotero/storage/B272KFL9/Chandra et al. - 2013 - Hastatic order in the heavy-fermion compound URus.pdf} } @article{ikeda_emergent_2012, @@ -381,65 +380,65 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = jul, year = {2012}, pages = {528-533}, - file = {/home/pants/.zotero/data/storage/9NYNGB45/Ikeda et al. - 2012 - Emergent rank-5 nematic order in URusub2subSi.pdf} + file = {/home/pants/.zotero/storage/9NYNGB45/Ikeda et al. - 2012 - Emergent rank-5 nematic order in URusub2subSi.pdf} } -@article{kiss_group_2005, - title = {Group Theory and Octupolar Order in \$\textbackslash{}mathrm\{\vphantom\}{{U}}\vphantom\{\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Ru}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$}, - volume = {71}, - abstract = {Recent experiments on URu2Si2URu2Si2 show that the low-pressure hidden order is nonmagnetic but it breaks time reversal invariance. Restricting our attention to local order parameters of 5f25f2 shells, we find that the best candidate for hidden order is staggered order of either Tz{$\beta$}T{$\beta$}z or TxyzTxyz octupoles. Group theoretical arguments for the effect of symmetry-lowering perturbations (magnetic field, mechanical stress) predict behavior in good overall agreement with observations. We illustrate our general arguments on the example of a five-state crystal field model which differs in several details from models discussed in the literature. The general appearance of the mean field phase diagram agrees with the experimental results. In particular, we find that (a) at zero magnetic field, there is a first-order phase boundary between octupolar order and large-moment antiferromagnetism with increasing hydrostatic pressure; (b) arbitrarily weak uniaxial pressure induces staggered magnetic moments in the octupolar phase; and (c) a new phase with different symmetry appears at large magnetic fields.}, - number = {5}, +@article{hassinger_temperature-pressure_2008, + title = {Temperature-Pressure Phase Diagram of \$\textbackslash{}mathrm\{\vphantom\}{{U}}\vphantom\{\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Ru}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$ from Resistivity Measurements and Ac Calorimetry: {{Hidden}} Order and {{Fermi}}-Surface Nesting}, + volume = {77}, + shorttitle = {Temperature-Pressure Phase Diagram of \$\textbackslash{}mathrm\{\vphantom\}{{U}}\vphantom\{\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Ru}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$ from Resistivity Measurements and Ac Calorimetry}, + abstract = {By performing combined resistivity and calorimetric experiments under pressure, we have determined a precise temperature-pressure (T,P) phase diagram of the heavy fermion compound URu2Si2. It will be compared with previous diagrams determined by elastic neutron diffraction and strain gauge techniques. At first glance, the low-pressure ordered phase referred to as hidden order is dominated by Fermi-surface nesting, which has strong consequences on the localized spin dynamics. The high-pressure phase is dominated by large moment antiferromagnetism (LMAF) coexisting with at least dynamical nesting needed to restore on cooling a local moment behavior. ac calorimetry confirms unambiguously that bulk superconductivity does not coexist with LMAF. URu2Si2 is one of the most spectacular examples of the dual itinerant and local character of uranium-based heavy fermion compounds.}, + number = {11}, journal = {Physical Review B}, - doi = {10.1103/physrevb.71.054415}, - author = {Kiss, Annam{\'a}ria and Fazekas, Patrik}, - month = feb, - year = {2005}, - pages = {054415}, - file = {/home/pants/.zotero/data/storage/YTARVDIM/Kiss and Fazekas - 2005 - Group theory and octupolar order in $mathrm U m.pdf} + doi = {10.1103/physrevb.77.115117}, + author = {Hassinger, E. and Knebel, G. and Izawa, K. and Lejay, P. and Salce, B. and Flouquet, J.}, + month = mar, + year = {2008}, + pages = {115117}, + file = {/home/pants/.zotero/storage/U5V8JT6U/Hassinger et al. - 2008 - Temperature-pressure phase diagram of $mathrm U .pdf} } -@article{varshni_temperature_1970, - title = {Temperature {{Dependence}} of the {{Elastic Constants}}}, - volume = {2}, - abstract = {The following two equations are proposed for the temperature dependence of the elastic stiffness constants: cij=c0ij-s(etT-1) and cij=a-bT2(T+c), where c0ij, s, t, a, b, and c are constants. The applicability of these two equations and that of Wachtman's equation is examined for 57 elastic constants of 22 substances. The first equation has a theoretical justification and gives the best over-all results. Neither of the three equations give the theoretically expected T4 dependence at low temperatures, and therefore they are not expected to give very accurate results at very low temperatures ({$\lessequivlnt\Theta$}D50). A new melting criterion is also examined.}, - number = {10}, +@article{choi_pressure-induced_2018, + title = {Pressure-Induced Rotational Symmetry Breaking in \$\{\textbackslash{}mathrm\{\vphantom{\}\}}{{URu}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$}, + volume = {98}, + abstract = {Phase transitions and symmetry are intimately linked. Melting of ice, for example, restores translation invariance. The mysterious hidden order (HO) phase of URu2Si2 has, despite relentless research efforts, kept its symmetry breaking element intangible. Here, we present a high-resolution x-ray diffraction study of the URu2Si2 crystal structure as a function of hydrostatic pressure. Below a critical pressure threshold pc{$\approx$}3 kbar, no tetragonal lattice symmetry breaking is observed even below the HO transition THO=17.5 K. For p{$>$}pc, however, a pressure-induced rotational symmetry breaking is identified with an onset temperatures TOR{$\sim$}100 K. The emergence of an orthorhombic phase is found and discussed in terms of an electronic nematic order that appears unrelated to the HO, but with possible relevance for the pressure-induced antiferromagnetic (AF) phase. Existing theories describe the HO and AF phases through an adiabatic continuity of a complex order parameter. Since none of these theories predicts a pressure-induced nematic order, our finding adds an additional symmetry breaking element to this long-standing problem.}, + number = {24}, journal = {Physical Review B}, - doi = {10.1103/physrevb.2.3952}, - author = {Varshni, Y. P.}, - month = nov, - year = {1970}, - pages = {3952-3958}, - file = {/home/pants/.zotero/data/storage/QN7TLJV7/Varshni - 1970 - Temperature Dependence of the Elastic Constants.pdf} + doi = {10/gf5c39}, + author = {Choi, J. and Ivashko, O. and Dennler, N. and Aoki, D. and {von Arx}, K. and Gerber, S. and Gutowski, O. and Fischer, M. H. and Strempfer, J. and {v. Zimmermann}, M. and Chang, J.}, + month = dec, + year = {2018}, + pages = {241113}, + file = {/home/pants/.zotero/storage/8IBGVH7U/Choi et al. - 2018 - Pressure-induced rotational symmetry breaking in $.pdf} } -@article{hornreich_critical_1975, - title = {Critical {{Behavior}} at the {{Onset}} of \$\textbackslash{}stackrel\{\textbackslash{}ensuremath\{\textbackslash{}rightarrow\}\}\{\textbackslash{}mathrm\{k\}\}\$-{{Space Instability}} on the \$\textbackslash{}ensuremath\{\textbackslash{}lambda\}\$ {{Line}}}, - volume = {35}, - abstract = {We calculate the critical behavior of systems having a multicritical point of a new type, hereafter called a Lifshitz point, which separates ordered phases with \textrightarrowk=0 and \textrightarrowk{$\not =$}0 along the {$\lambda$} line. For anisotropic systems, the correlation function is described in terms of four critical exponents, whereas for isotropic systems two exponents suffice. Critical exponents are calculated using an {$\epsilon$}-type expansion.}, - number = {25}, - journal = {Physical Review Letters}, - doi = {10.1103/PhysRevLett.35.1678}, - author = {Hornreich, R. M. and Luban, Marshall and Shtrikman, S.}, - month = dec, - year = {1975}, - pages = {1678-1681}, - file = {/home/pants/.zotero/data/storage/GBYIESIW/Hornreich et al_1975_Critical Behavior at the Onset of.pdf;/home/pants/.zotero/data/storage/KBYQHWSH/PhysRevLett.35.html} +@article{chandra_origin_2013, + title = {Origin of the {{Large Anisotropy}} in The\$\textbackslash{}upchi\${{3Anomaly inURu2Si2}}}, + volume = {449}, + issn = {1742-6596}, + abstract = {Motivated by recent quantum oscillations experiments on U Ru2Si2, we discuss the microscopic origin of the large anisotropy observed many years ago in the anomaly of the nonlinear susceptibility in this same material. We show that the magnitude of this anomaly emerges naturally from hastatic order, a proposal for hidden order that is a two-component spinor arising from the hybridization of a non-Kramers {$\Gamma$}5 doublet with Kramers conduction electrons. A prediction is made for the angular anisotropy of the nonlinear susceptibility anomaly as a test of this proposed order parameter for U Ru2Si2.}, + language = {en}, + journal = {Journal of Physics: Conference Series}, + doi = {10.1088/1742-6596/449/1/012026}, + author = {Chandra, P. and Coleman, P. and Flint, R.}, + month = jul, + year = {2013}, + pages = {012026}, + file = {/home/pants/.zotero/storage/7K2FNND4/Chandra et al. - 2013 - Origin of the Large Anisotropy in the$upchi$3Anom.pdf} } -@article{inoue_high-field_2001, - series = {Proceedings of the {{Sixth International}} {{Symposium}} on {{Research}} in {{High Magnetic Fields}}}, - title = {High-Field Magnetization of {{URu2Si2}} under High Pressure}, - volume = {294-295}, - issn = {0921-4526}, - abstract = {The temperature dependence of the magnetic susceptibility and the high-field magnetization up to 55T are measured for URu2Si2 under high pressures up to 1GPa. Both T{$\chi$}max and TN in the susceptibility increase with increasing pressure. The value of the susceptibility below T{$\chi$}max decreases with increasing pressure. The three high-field metamagnetic transitions at Hc1=35.1T, Hc2=36.5T and Hc3=39.6T at ambient pressure, show different pressure-dependent behaviors. The metamagnetic transition at Hc1 broadens but survives and its transition field increases with increasing pressure. However, the transition at Hc2 is smeared out and disappears above 0.4GPa. The transition at Hc3 broadens more clearly than the transition at Hc1. The fact that both T{$\chi$}max and the metamagnetic transition fields increase suggests that the interaction between the f-electrons and the conduction electrons is enhanced by pressure.}, - journal = {Physica B: Condensed Matter}, - doi = {10.1016/S0921-4526(00)00657-8}, - author = {Inoue, T. and Kindo, K. and Okuni, H. and Sugiyama, K. and Haga, Y. and Yamamoto, E. and Kobayashi, T. C. and Uwatoko, Y. and Onuki, Y.}, - month = jan, - year = {2001}, - keywords = {High pressure,High-field magnetization,Metamagnetic transition,URuSi}, - pages = {271-275}, - file = {/home/pants/.zotero/data/storage/CDTQB6PI/Inoue et al_2001_High-field magnetization of URu2Si2 under high pressure.pdf;/home/pants/.zotero/data/storage/323PS9NS/S0921452600006578.html} +@article{meng_imaging_2013, + title = {Imaging the {{Three}}-{{Dimensional Fermi}}-{{Surface Pairing}} near the {{Hidden}}-{{Order Transition}} in \$\{\textbackslash{}mathrm\{\vphantom{\}\}}{{URu}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$ {{Using Angle}}-{{Resolved Photoemission Spectroscopy}}}, + volume = {111}, + abstract = {We report angle-resolved photoemission spectroscopy experiments probing deep into the hidden-order state of URu2Si2, utilizing tunable photon energies with sufficient energy and momentum resolution to detect the near Fermi-surface (FS) behavior. Our results reveal (i) the full itinerancy of the 5f electrons, (ii) the crucial three-dimensional k-space nature of the FS and its critical nesting vectors, in good comparison with density-functional theory calculations, and (iii) the existence of hot-spot lines and pairing of states at the FS, leading to FS gapping in the hidden-order phase.}, + number = {12}, + journal = {Physical Review Letters}, + doi = {10.1103/PhysRevLett.111.127002}, + author = {Meng, Jian-Qiao and Oppeneer, Peter M. and Mydosh, John A. and Riseborough, Peter S. and Gofryk, Krzysztof and Joyce, John J. and Bauer, Eric D. and Li, Yinwan and Durakiewicz, Tomasz}, + month = sep, + year = {2013}, + pages = {127002}, + file = {/home/pants/.zotero/storage/EBTUZTN7/Meng et al_2013_Imaging the Three-Dimensional Fermi-Surface Pairing near the Hidden-Order.pdf;/home/pants/.zotero/storage/U2Z93ZIJ/PhysRevLett.111.html} } @article{shekhter_bounding_2013, @@ -456,81 +455,69 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = jun, year = {2013}, pages = {75-77}, - file = {/home/pants/.zotero/data/storage/Y3X6VXIK/Shekhter et al_2013_Bounding the pseudogap with a line of phase transitions in.pdf;/home/pants/.zotero/data/storage/ZZ3MR77N/nature12165.html} + file = {/home/pants/.zotero/storage/Y3X6VXIK/Shekhter et al_2013_Bounding the pseudogap with a line of phase transitions in.pdf;/home/pants/.zotero/storage/ZZ3MR77N/nature12165.html} } -@article{meng_imaging_2013, - title = {Imaging the {{Three}}-{{Dimensional Fermi}}-{{Surface Pairing}} near the {{Hidden}}-{{Order Transition}} in \$\{\textbackslash{}mathrm\{\vphantom{\}\}}{{URu}}\vphantom\{\}\vphantom\{\}\_\{2\}\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$ {{Using Angle}}-{{Resolved Photoemission Spectroscopy}}}, - volume = {111}, - abstract = {We report angle-resolved photoemission spectroscopy experiments probing deep into the hidden-order state of URu2Si2, utilizing tunable photon energies with sufficient energy and momentum resolution to detect the near Fermi-surface (FS) behavior. Our results reveal (i) the full itinerancy of the 5f electrons, (ii) the crucial three-dimensional k-space nature of the FS and its critical nesting vectors, in good comparison with density-functional theory calculations, and (iii) the existence of hot-spot lines and pairing of states at the FS, leading to FS gapping in the hidden-order phase.}, - number = {12}, - journal = {Physical Review Letters}, - doi = {10.1103/PhysRevLett.111.127002}, - author = {Meng, Jian-Qiao and Oppeneer, Peter M. and Mydosh, John A. and Riseborough, Peter S. and Gofryk, Krzysztof and Joyce, John J. and Bauer, Eric D. and Li, Yinwan and Durakiewicz, Tomasz}, - month = sep, - year = {2013}, - pages = {127002}, - file = {/home/pants/.zotero/data/storage/EBTUZTN7/Meng et al_2013_Imaging the Three-Dimensional Fermi-Surface Pairing near the Hidden-Order.pdf;/home/pants/.zotero/data/storage/U2Z93ZIJ/PhysRevLett.111.html} +@article{inoue_high-field_2001, + series = {Proceedings of the {{Sixth International}} {{Symposium}} on {{Research}} in {{High Magnetic Fields}}}, + title = {High-Field Magnetization of {{URu2Si2}} under High Pressure}, + volume = {294-295}, + issn = {0921-4526}, + abstract = {The temperature dependence of the magnetic susceptibility and the high-field magnetization up to 55T are measured for URu2Si2 under high pressures up to 1GPa. Both T{$\chi$}max and TN in the susceptibility increase with increasing pressure. The value of the susceptibility below T{$\chi$}max decreases with increasing pressure. The three high-field metamagnetic transitions at Hc1=35.1T, Hc2=36.5T and Hc3=39.6T at ambient pressure, show different pressure-dependent behaviors. The metamagnetic transition at Hc1 broadens but survives and its transition field increases with increasing pressure. However, the transition at Hc2 is smeared out and disappears above 0.4GPa. The transition at Hc3 broadens more clearly than the transition at Hc1. The fact that both T{$\chi$}max and the metamagnetic transition fields increase suggests that the interaction between the f-electrons and the conduction electrons is enhanced by pressure.}, + journal = {Physica B: Condensed Matter}, + doi = {10.1016/S0921-4526(00)00657-8}, + author = {Inoue, T. and Kindo, K. and Okuni, H. and Sugiyama, K. and Haga, Y. and Yamamoto, E. and Kobayashi, T. C. and Uwatoko, Y. and Onuki, Y.}, + month = jan, + year = {2001}, + keywords = {High pressure,High-field magnetization,Metamagnetic transition,URuSi}, + pages = {271-275}, + file = {/home/pants/.zotero/storage/CDTQB6PI/Inoue et al_2001_High-field magnetization of URu2Si2 under high pressure.pdf;/home/pants/.zotero/storage/323PS9NS/S0921452600006578.html} } -@article{chandra_origin_2013, - title = {Origin of the {{Large Anisotropy}} in The\$\textbackslash{}upchi\${{3Anomaly inURu2Si2}}}, - volume = {449}, - issn = {1742-6596}, - abstract = {Motivated by recent quantum oscillations experiments on U Ru2Si2, we discuss the microscopic origin of the large anisotropy observed many years ago in the anomaly of the nonlinear susceptibility in this same material. We show that the magnitude of this anomaly emerges naturally from hastatic order, a proposal for hidden order that is a two-component spinor arising from the hybridization of a non-Kramers {$\Gamma$}5 doublet with Kramers conduction electrons. A prediction is made for the angular anisotropy of the nonlinear susceptibility anomaly as a test of this proposed order parameter for U Ru2Si2.}, - language = {en}, - journal = {Journal of Physics: Conference Series}, - doi = {10.1088/1742-6596/449/1/012026}, - author = {Chandra, P. and Coleman, P. and Flint, R.}, - month = jul, - year = {2013}, - pages = {012026}, - file = {/home/pants/.zotero/data/storage/7K2FNND4/Chandra et al. - 2013 - Origin of the Large Anisotropy in the$upchi$3Anom.pdf} +@article{hornreich_critical_1975, + title = {Critical {{Behavior}} at the {{Onset}} of \$\textbackslash{}stackrel\{\textbackslash{}ensuremath\{\textbackslash{}rightarrow\}\}\{\textbackslash{}mathrm\{k\}\}\$-{{Space Instability}} on the \$\textbackslash{}ensuremath\{\textbackslash{}lambda\}\$ {{Line}}}, + volume = {35}, + abstract = {We calculate the critical behavior of systems having a multicritical point of a new type, hereafter called a Lifshitz point, which separates ordered phases with \textrightarrowk=0 and \textrightarrowk{$\not =$}0 along the {$\lambda$} line. For anisotropic systems, the correlation function is described in terms of four critical exponents, whereas for isotropic systems two exponents suffice. Critical exponents are calculated using an {$\epsilon$}-type expansion.}, + number = {25}, + journal = {Physical Review Letters}, + doi = {10.1103/PhysRevLett.35.1678}, + author = {Hornreich, R. M. and Luban, Marshall and Shtrikman, S.}, + month = dec, + year = {1975}, + pages = {1678-1681}, + file = {/home/pants/.zotero/storage/GBYIESIW/Hornreich et al_1975_Critical Behavior at the Onset of.pdf;/home/pants/.zotero/storage/KBYQHWSH/PhysRevLett.35.html} } -@article{garel_commensurability_1976, - title = {Commensurability Effects on the Critical Behaviour of Systems with Helical Ordering}, - volume = {9}, - issn = {0022-3719}, - abstract = {The critical behaviour of an m-component spin system with helical ordering is studied using the renormalization group method to order epsilon 2 (where epsilon =4-d). For m=1 and 2 the system is equivalent to a 2m-vector model. For m=3 a first-order transition is expected. The effect of the commensurability of the helical structure with the lattice has been considered and is shown in certain situations to change the order of the transition.}, +@article{selke_monte_1978, + title = {Monte Carlo Calculations near a Uniaxial {{Lifshitz}} Point}, + volume = {29}, + issn = {1431-584X}, + abstract = {The Monte Carlo method is applied to a threedimensional Ising model with nearest neighbour ferromagnetic interactions and next nearest neighbour antiferromagnetic interactions along one axis only. Special emphasis is given to the critical behaviour near the Lifshitz point.}, language = {en}, - number = {10}, - journal = {Journal of Physics C: Solid State Physics}, - doi = {2011031909475300}, - author = {Garel, T. and Pfeuty, P.}, - month = may, - year = {1976}, - pages = {L245--L249}, - file = {/home/pants/.zotero/data/storage/34KTXA6I/Garel_Pfeuty_1976_Commensurability effects on the critical behaviour of systems with helical.pdf} -} - -@article{nicoll_onset_1977, - title = {Onset of Helical Order}, - volume = {86-88}, - issn = {0378-4363}, - abstract = {Renormalization group methods are used to describe systems which model critical phenomena at the onset of helical order. This onset is marked by a change in the ``bare propagator'' used in perturbation theory from a k2-dependence to a more general form. We consider systems which in the non-helical region exhibit O simultaneously critical phases. Results are given to first order in an {$\epsilon$}-expansion. For the isotropic case of k2L dependence and O = 2, we give {$\eta$} to first order in 1/n for d- {$\leqslant$} d {$\leqslant$} d+ where d+- are upper and lower borderline dimensions.}, - journal = {Physica B+C}, - doi = {10.1016/0378-4363(77)90620-9}, - author = {Nicoll, J. F. and Tuthill, G. F. and Chang, T. S. and Stanley, H. E.}, - month = jan, - year = {1977}, - pages = {618-620}, - file = {/home/pants/.zotero/data/storage/ZLV5YFH6/Nicoll et al_1977_Onset of helical order.pdf;/home/pants/.zotero/data/storage/84ZZT6CN/0378436377906209.html} + number = {2}, + journal = {Zeitschrift f{\"u}r Physik B Condensed Matter}, + doi = {10.1007/BF01313198}, + author = {Selke, Walter}, + month = jun, + year = {1978}, + keywords = {Complex System,Neural Network,Spectroscopy,State Physics,Monte Carlo Method}, + pages = {133-137}, + file = {/home/pants/.zotero/storage/5NRZEWP8/Selke_1978_Monte carlo calculations near a uniaxial Lifshitz point.pdf} } -@article{nicoll_renormalization_1976, - title = {Renormalization Group Calculation for Critical Points of Higher Order with General Propagator}, - volume = {58}, +@article{hornreich_critical_1975-1, + title = {Critical Exponents at a {{Lifshitz}} Point to {{O}}(1/n)}, + volume = {55}, issn = {0375-9601}, - abstract = {We give first order perturbation results for the critical point exponents at order O critical points with anisotropic propagators. The exponent {$\eta$} is calculated to second order for isotropic propagators, and all O; 1/n expansion results are given for O = 2.}, - number = {1}, + abstract = {The critical exponents at a general Lifshitz point are calculated in the spherical model limit, as are those of an isotropic Lifshitz point to O(1/n). These results are in exact agreement in the overlap region with those obtained using an {$\epsilon$}-expansion.}, + number = {5}, journal = {Physics Letters A}, - doi = {10.1016/0375-9601(76)90527-2}, - author = {Nicoll, J. F. and Tuthill, G. F. and Chang, T. S. and Stanley, H. E.}, - month = jul, - year = {1976}, - pages = {1-2}, - file = {/home/pants/.zotero/data/storage/55AS69UD/Nicoll et al_1976_Renormalization group calculation for critical points of higher order with.pdf;/home/pants/.zotero/data/storage/L6WH4D36/0375960176905272.html} + doi = {10.1016/0375-9601(75)90465-X}, + author = {Hornreich, R. M. and Luban, M. and Shtrikman, S.}, + month = dec, + year = {1975}, + pages = {269-270}, + file = {/home/pants/.zotero/storage/RED39SK4/Hornreich et al_1975_Critical exponents at a Lifshitz point to O(1-n).pdf;/home/pants/.zotero/storage/X8UJ5CHZ/037596017590465X.html} } @article{hornreich_exactly_1977, @@ -545,61 +532,80 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature month = feb, year = {1977}, pages = {465-470}, - file = {/home/pants/.zotero/data/storage/5MFN7M9Z/Hornreich et al_1977_Exactly solvable model exhibiting a multicritical point.pdf;/home/pants/.zotero/data/storage/CZNV72TI/0378437177900425.html} + file = {/home/pants/.zotero/storage/5MFN7M9Z/Hornreich et al_1977_Exactly solvable model exhibiting a multicritical point.pdf;/home/pants/.zotero/storage/CZNV72TI/0378437177900425.html} } -@article{hornreich_critical_1975-1, - title = {Critical Exponents at a {{Lifshitz}} Point to {{O}}(1/n)}, - volume = {55}, +@article{nicoll_renormalization_1976, + title = {Renormalization Group Calculation for Critical Points of Higher Order with General Propagator}, + volume = {58}, issn = {0375-9601}, - abstract = {The critical exponents at a general Lifshitz point are calculated in the spherical model limit, as are those of an isotropic Lifshitz point to O(1/n). These results are in exact agreement in the overlap region with those obtained using an {$\epsilon$}-expansion.}, - number = {5}, + abstract = {We give first order perturbation results for the critical point exponents at order O critical points with anisotropic propagators. The exponent {$\eta$} is calculated to second order for isotropic propagators, and all O; 1/n expansion results are given for O = 2.}, + number = {1}, journal = {Physics Letters A}, - doi = {10.1016/0375-9601(75)90465-X}, - author = {Hornreich, R. M. and Luban, M. and Shtrikman, S.}, - month = dec, - year = {1975}, - pages = {269-270}, - file = {/home/pants/.zotero/data/storage/RED39SK4/Hornreich et al_1975_Critical exponents at a Lifshitz point to O(1-n).pdf;/home/pants/.zotero/data/storage/X8UJ5CHZ/037596017590465X.html} + doi = {10.1016/0375-9601(76)90527-2}, + author = {Nicoll, J. F. and Tuthill, G. F. and Chang, T. S. and Stanley, H. E.}, + month = jul, + year = {1976}, + pages = {1-2}, + file = {/home/pants/.zotero/storage/55AS69UD/Nicoll et al_1976_Renormalization group calculation for critical points of higher order with.pdf;/home/pants/.zotero/storage/L6WH4D36/0375960176905272.html} } -@article{selke_monte_1978, - title = {Monte Carlo Calculations near a Uniaxial {{Lifshitz}} Point}, - volume = {29}, - issn = {1431-584X}, - abstract = {The Monte Carlo method is applied to a threedimensional Ising model with nearest neighbour ferromagnetic interactions and next nearest neighbour antiferromagnetic interactions along one axis only. Special emphasis is given to the critical behaviour near the Lifshitz point.}, +@article{nicoll_onset_1977, + title = {Onset of Helical Order}, + volume = {86-88}, + issn = {0378-4363}, + abstract = {Renormalization group methods are used to describe systems which model critical phenomena at the onset of helical order. This onset is marked by a change in the ``bare propagator'' used in perturbation theory from a k2-dependence to a more general form. We consider systems which in the non-helical region exhibit O simultaneously critical phases. Results are given to first order in an {$\epsilon$}-expansion. For the isotropic case of k2L dependence and O = 2, we give {$\eta$} to first order in 1/n for d- {$\leqslant$} d {$\leqslant$} d+ where d+- are upper and lower borderline dimensions.}, + journal = {Physica B+C}, + doi = {10.1016/0378-4363(77)90620-9}, + author = {Nicoll, J. F. and Tuthill, G. F. and Chang, T. S. and Stanley, H. E.}, + month = jan, + year = {1977}, + pages = {618-620}, + file = {/home/pants/.zotero/storage/ZLV5YFH6/Nicoll et al_1977_Onset of helical order.pdf;/home/pants/.zotero/storage/84ZZT6CN/0378436377906209.html} +} + +@article{garel_commensurability_1976, + title = {Commensurability Effects on the Critical Behaviour of Systems with Helical Ordering}, + volume = {9}, + issn = {0022-3719}, + abstract = {The critical behaviour of an m-component spin system with helical ordering is studied using the renormalization group method to order epsilon 2 (where epsilon =4-d). For m=1 and 2 the system is equivalent to a 2m-vector model. For m=3 a first-order transition is expected. The effect of the commensurability of the helical structure with the lattice has been considered and is shown in certain situations to change the order of the transition.}, language = {en}, - number = {2}, - journal = {Zeitschrift f{\"u}r Physik B Condensed Matter}, - doi = {10.1007/BF01313198}, - author = {Selke, Walter}, - month = jun, - year = {1978}, - keywords = {Complex System,Neural Network,Spectroscopy,State Physics,Monte Carlo Method}, - pages = {133-137}, - file = {/home/pants/.zotero/data/storage/5NRZEWP8/Selke_1978_Monte carlo calculations near a uniaxial Lifshitz point.pdf} + number = {10}, + journal = {Journal of Physics C: Solid State Physics}, + doi = {2011031909475300}, + author = {Garel, T. and Pfeuty, P.}, + month = may, + year = {1976}, + pages = {L245--L249}, + file = {/home/pants/.zotero/storage/34KTXA6I/Garel_Pfeuty_1976_Commensurability effects on the critical behaviour of systems with helical.pdf} } -@article{harrison_hidden_nodate, - archivePrefix = {arXiv}, - eprinttype = {arxiv}, - eprint = {1902.06588}, - title = {Hidden Valence Transition in {{URu2Si2}}?}, - abstract = {The term "hidden order" refers to an as yet unidentified form of broken-symmetry order parameter that is presumed to exist in the strongly correlated electron system URu2Si2 on the basis of the reported similarity of the heat capacity at its phase transition at To\textasciitilde{}17 K to that produced by Bardeen-Cooper-Schrieffer (BCS) mean field theory. Here we show that the phase boundary in URu2Si2 has the elliptical form expected for an entropy-driven phase transition, as has been shown to accompany a change in valence. We show one characteristic feature of such a transition is that the ratio of the critical magnetic field to the critical temperature is defined solely in terms of the effective quasiparticle g-factor, which we find to be in quantitative agreement with prior g-factor measurements. We further find the anomaly in the heat capacity at To to be significantly sharper than a BCS phase transition, and, once quasiparticle excitations across the hybridization gap are taken into consideration, loses its resemblance to a second order phase transition. Our findings imply that a change in valence dominates the thermodynamics of the phase boundary in URu2Si2, and eclipses any significant contribution to the thermodynamics from a hidden order parameter.}, - author = {Harrison, Neil and Jaime, Marcelo}, - keywords = {Condensed Matter - Strongly Correlated Electrons}, - file = {/home/pants/.zotero/data/storage/79NX4WI3/Harrison and Jaime - 2019 - Hidden valence transition in URu2Si2.pdf} +@article{bak_commensurate_1982, + title = {Commensurate Phases, Incommensurate Phases and the Devil's Staircase}, + volume = {45}, + issn = {0034-4885, 1361-6633}, + number = {6}, + journal = {Reports on Progress in Physics}, + doi = {10.1088/0034-4885/45/6/001}, + author = {Bak, P}, + month = jun, + year = {1982}, + pages = {587-629}, + file = {/home/pants/.zotero/storage/TYKMSDX7/Bak - 1982 - Commensurate phases, incommensurate phases and the.pdf} } -@article{ghosh_single-component_nodate, - archivePrefix = {arXiv}, - eprinttype = {arxiv}, - eprint = {1903.00552}, - title = {Single-{{Component Order Parameter}} in {{URu}}\$\_2\${{Si}}\$\_2\$ {{Uncovered}} by {{Resonant Ultrasound Spectroscopy}} and {{Machine Learning}}}, - abstract = {URu\$\_2\$Si\$\_2\$ exhibits a clear phase transition at T\$\_\{HO\}= 17.5\textasciitilde\$K to a low-temperature phase known as "hidden order" (HO). Even the most basic information needed to construct a theory of this state---such as the number of components in the order parameter---has been lacking. Here we use resonant ultrasound spectroscopy (RUS) and machine learning to determine that the order parameter of HO is one-dimensional (singlet), ruling out a large class of theories based on two-dimensional (doublet) order parameters. This strict constraint is independent of any microscopic mechanism, and independent of other symmetries that HO may break. Our technique is general for second-order phase transitions, and can discriminate between nematic (singlet) versus loop current (doublet) order in the high-\textbackslash{}Tc cuprates, and conventional (singlet) versus the proposed \$p\_x+ip\_y\$ (doublet) superconductivity in Sr\$\_2\$RuO\$\_4\$. The machine learning framework we develop should be readily adaptable to other spectroscopic techniques where missing resonances confound traditional analysis, such as NMR.}, - author = {Ghosh, Sayak and Matty, Michael and Baumbach, Ryan and Bauer, Eric D. and Modic, K. A. and Shekhter, Arkady and Mydosh, J. A. and Kim, Eun-Ah and Ramshaw, B. J.}, - keywords = {Condensed Matter - Strongly Correlated Electrons,Physics - Data Analysis; Statistics and Probability}, - file = {/home/pants/.zotero/data/storage/XIE9PPL6/Ghosh et al. - 2019 - Single-Component Order Parameter in URu$_2$Si$_2$ .pdf} +@article{luthi_sound_1970, + title = {Sound {{Propagation}} near the {{Structural Phase Transition}} in {{Strontium Titanate}}}, + volume = {2}, + abstract = {Finite ultrasonic velocity changes at the structural phase transition in SrTi03 are observed for different modes. They are interrelated and correlated by theory. No critical effects are observed.}, + number = {4}, + journal = {Physical Review B}, + doi = {10.1103/PhysRevB.2.1211}, + author = {L{\"u}thi, B. and Moran, T. J.}, + month = aug, + year = {1970}, + pages = {1211-1214}, + file = {/home/pants/.zotero/storage/RQZGTK9L/Lüthi and Moran - 1970 - Sound Propagation near the Structural Phase Transi.pdf} } @article{ramshaw_avoided_2015, @@ -614,38 +620,78 @@ Raman spectroscopy is used to uncover an unusual ordering in the low-temperature author = {Ramshaw, B. J. and Shekhter, Arkady and McDonald, Ross D. and Betts, Jon B. and Mitchell, J. N. and Tobash, P. H. and Mielke, C. H. and Bauer, E. D. and Migliori, Albert}, month = mar, year = {2015}, - keywords = {heavy fermions,quantum criticality,resonant ultrasound spectroscopy,unconventional superconductivity,valence fluctuations}, + keywords = {quantum criticality,heavy fermions,resonant ultrasound spectroscopy,unconventional superconductivity,valence fluctuations}, pages = {3285-3289}, - file = {/home/pants/.zotero/data/storage/ERT8A25E/Ramshaw et al. - 2015 - Avoided valence transition in a plutonium supercon.pdf}, + file = {/home/pants/.zotero/storage/ERT8A25E/Ramshaw et al. - 2015 - Avoided valence transition in a plutonium supercon.pdf}, pmid = {25737548} } -@article{luthi_sound_1970, - title = {Sound {{Propagation}} near the {{Structural Phase Transition}} in {{Strontium Titanate}}}, - volume = {2}, - abstract = {Finite ultrasonic velocity changes at the structural phase transition in SrTi03 are observed for different modes. They are interrelated and correlated by theory. No critical effects are observed.}, - number = {4}, +@article{ghosh_single-component_nodate, + archivePrefix = {arXiv}, + eprinttype = {arxiv}, + eprint = {1903.00552}, + title = {Single-{{Component Order Parameter}} in {{URu}}\$\_2\${{Si}}\$\_2\$ {{Uncovered}} by {{Resonant Ultrasound Spectroscopy}} and {{Machine Learning}}}, + abstract = {URu\$\_2\$Si\$\_2\$ exhibits a clear phase transition at T\$\_\{HO\}= 17.5\textasciitilde\$K to a low-temperature phase known as "hidden order" (HO). Even the most basic information needed to construct a theory of this state---such as the number of components in the order parameter---has been lacking. Here we use resonant ultrasound spectroscopy (RUS) and machine learning to determine that the order parameter of HO is one-dimensional (singlet), ruling out a large class of theories based on two-dimensional (doublet) order parameters. This strict constraint is independent of any microscopic mechanism, and independent of other symmetries that HO may break. Our technique is general for second-order phase transitions, and can discriminate between nematic (singlet) versus loop current (doublet) order in the high-\textbackslash{}Tc cuprates, and conventional (singlet) versus the proposed \$p\_x+ip\_y\$ (doublet) superconductivity in Sr\$\_2\$RuO\$\_4\$. The machine learning framework we develop should be readily adaptable to other spectroscopic techniques where missing resonances confound traditional analysis, such as NMR.}, + author = {Ghosh, Sayak and Matty, Michael and Baumbach, Ryan and Bauer, Eric D. and Modic, K. A. and Shekhter, Arkady and Mydosh, J. A. and Kim, Eun-Ah and Ramshaw, B. J.}, + keywords = {Condensed Matter - Strongly Correlated Electrons,Physics - Data Analysis; Statistics and Probability}, + file = {/home/pants/.zotero/storage/XIE9PPL6/Ghosh et al. - 2019 - Single-Component Order Parameter in URu$_2$Si$_2$ .pdf} +} + +@article{harrison_hidden_nodate, + archivePrefix = {arXiv}, + eprinttype = {arxiv}, + eprint = {1902.06588}, + title = {Hidden Valence Transition in {{URu2Si2}}?}, + abstract = {The term "hidden order" refers to an as yet unidentified form of broken-symmetry order parameter that is presumed to exist in the strongly correlated electron system URu2Si2 on the basis of the reported similarity of the heat capacity at its phase transition at To\textasciitilde{}17 K to that produced by Bardeen-Cooper-Schrieffer (BCS) mean field theory. Here we show that the phase boundary in URu2Si2 has the elliptical form expected for an entropy-driven phase transition, as has been shown to accompany a change in valence. We show one characteristic feature of such a transition is that the ratio of the critical magnetic field to the critical temperature is defined solely in terms of the effective quasiparticle g-factor, which we find to be in quantitative agreement with prior g-factor measurements. We further find the anomaly in the heat capacity at To to be significantly sharper than a BCS phase transition, and, once quasiparticle excitations across the hybridization gap are taken into consideration, loses its resemblance to a second order phase transition. Our findings imply that a change in valence dominates the thermodynamics of the phase boundary in URu2Si2, and eclipses any significant contribution to the thermodynamics from a hidden order parameter.}, + author = {Harrison, Neil and Jaime, Marcelo}, + keywords = {Condensed Matter - Strongly Correlated Electrons}, + file = {/home/pants/.zotero/storage/79NX4WI3/Harrison and Jaime - 2019 - Hidden valence transition in URu2Si2.pdf} +} + +@article{broholm_magnetic_1991, + title = {Magnetic Excitations in the Heavy-Fermion Superconductor \$\{\textbackslash{}mathrm\{\vphantom{\}\}}{{URu}}\vphantom\{\}\vphantom\{\}\_\{2\}\$\$\{\textbackslash{}mathrm\{\vphantom{\}\}}{{Si}}\vphantom\{\}\vphantom\{\}\_\{2\}\$}, + volume = {43}, + abstract = {Antiferromagnetic order and fluctuations in the heavy-fermion superconductor URu2Si2 have been studied by magnetic neutron scattering. Below TN=17.5 K, URu2Si2 is a type-I antiferromagnet with an anomalously small ordered moment of (0.04{$\pm$}0.01){$\mu$}B polarized along the tetragonal c axis. Dispersive resonant excitations exist in the ordered state with a zone-center gap of 0.43 THz. The excitations are polarized along the ordered moment and have a large dipolar matrix element, which suggests that they are coupled transitions between singlet crystal-field-like states. For energy transfer above 3 THz, peaks have not been identified in the magnetic excitation spectra, but instead a continuous spectrum of scattering peaked around the ordering wave vector indicates the presence of overdamped antiferromagnetically correlated spin fluctuations. Upon heating above TN, the resonant excitations abruptly become heavily damped but the magnetic scattering at higher energies does not change at TN. Instead, the disappearance of the antiferromagnetic modulation of the higher-energy scattering coincides with the maximum in the resistivity of URu2Si2.}, + number = {16}, journal = {Physical Review B}, - doi = {10.1103/PhysRevB.2.1211}, - author = {L{\"u}thi, B. and Moran, T. J.}, - month = aug, - year = {1970}, - pages = {1211-1214}, - file = {/home/pants/.zotero/data/storage/RQZGTK9L/Lüthi and Moran - 1970 - Sound Propagation near the Structural Phase Transi.pdf} + doi = {10.1103/PhysRevB.43.12809}, + author = {Broholm, C. and Lin, H. and Matthews, P. T. and Mason, T. E. and Buyers, W. J. L. and Collins, M. F. and Menovsky, A. A. and Mydosh, J. A. and Kjems, J. K.}, + month = jun, + year = {1991}, + pages = {12809-12822}, + file = {/home/pants/.zotero/storage/XSPQ8TDT/Broholm et al_1991_Magnetic excitations in the heavy-fermion superconductor.pdf;/home/pants/.zotero/storage/ALCY8T8W/PhysRevB.43.html} } -@article{bak_commensurate_1982, - title = {Commensurate Phases, Incommensurate Phases and the Devil's Staircase}, - volume = {45}, - issn = {0034-4885, 1361-6633}, +@article{wiebe_gapped_2007, + title = {Gapped Itinerant Spin Excitations Account for Missing Entropy in the Hidden-Order State of {{URu}}{\textsubscript{2}}{{Si}}{\textsubscript{2}}}, + volume = {3}, + copyright = {2007 Nature Publishing Group}, + issn = {1745-2481}, + abstract = {Many correlated electron materials, such as high-temperature superconductors1, geometrically frustrated oxides2 and low-dimensional magnets3,4, are still objects of fruitful study because of the unique properties that arise owing to poorly understood many-body effects. Heavy-fermion metals5\textemdash{}materials that have high effective electron masses due to those effects\textemdash{}represent a class of materials with exotic properties, ranging from unusual magnetism, unconventional superconductivity and `hidden' order parameters6. The heavy-fermion superconductor URu2Si2 has held the attention of physicists for the past two decades owing to the presence of a `hidden-order' phase below 17.5 K. Neutron scattering measurements indicate that the ordered moment is 0.03{$\mu$}B, much too small to account for the large heat-capacity anomaly at 17.5 K. We present recent neutron scattering experiments that unveil a new piece of this puzzle\textemdash{}the spin-excitation spectrum above 17.5 K exhibits well-correlated, itinerant-like spin excitations up to at least 10 meV, emanating from incommensurate wavevectors. The large entropy change associated with the presence of an energy gap in the excitations explains the reduction in the electronic specific heat through the transition.}, + language = {en}, + number = {2}, + journal = {Nature Physics}, + doi = {10.1038/nphys522}, + author = {Wiebe, C. R. and Janik, J. A. and MacDougall, G. J. and Luke, G. M. and Garrett, J. D. and Zhou, H. D. and Jo, Y.-J. and Balicas, L. and Qiu, Y. and Copley, J. R. D. and Yamani, Z. and Buyers, W. J. L.}, + month = feb, + year = {2007}, + pages = {96-99}, + file = {/home/pants/.zotero/storage/H775USBY/Wiebe et al_2007_Gapped itinerant spin excitations account for missing entropy in the.pdf;/home/pants/.zotero/storage/NAURLM99/nphys522.html} +} + +@article{bourdarot_precise_2010, + title = {Precise {{Study}} of the {{Resonance}} at {{Q0}}=(1,0,0) in {{URu2Si2}}}, + volume = {79}, + issn = {0031-9015}, + abstract = {New inelastic neutron scattering experiments have been performed on URu 2 Si 2 with special focus on the response at Q 0 =(1,0,0), which is a clear signature of the hidden order (HO) phase of the compound. With polarized inelastic neutron experiments, it is clearly shown that below the HO temperature ( T 0 =17.8 K) a collective excitation (the magnetic resonance at E 0 {$\simeq$}1.7 meV) as well as a magnetic continuum co-exist. Careful measurements of the temperature dependence of the resonance lead to the observation that its position shifts abruptly in temperature with an activation law governed by the partial gap opening and that its integrated intensity has a BCS-type temperature dependence. Discussion with respect to recent theoretical development is made.}, number = {6}, - journal = {Reports on Progress in Physics}, - doi = {10.1088/0034-4885/45/6/001}, - author = {Bak, P}, + journal = {Journal of the Physical Society of Japan}, + doi = {10.1143/JPSJ.79.064719}, + author = {Bourdarot, Frederic and Hassinger, Elena and Raymond, Stephane and Aoki, Dai and Taufour, Valentin and Regnault, Louis-Pierre and Flouquet, Jacques}, month = jun, - year = {1982}, - pages = {587-629}, - file = {/home/pants/.zotero/data/storage/TYKMSDX7/Bak - 1982 - Commensurate phases, incommensurate phases and the.pdf} + year = {2010}, + pages = {064719}, + file = {/home/pants/.zotero/storage/IPNNKJIA/Bourdarot et al_2010_Precise Study of the Resonance at Q0=(1,0,0) in URu2Si2.pdf;/home/pants/.zotero/storage/QYBEHN3M/JPSJ.79.html} } @@ -444,15 +444,16 @@ $q_*$ should continuously vanish. Far from the Lifshitz point we expect the wavevector to lock into values commensurate with the space group of the lattice, and moreover that at zero pressure, where the \rus\ data here was collected, the half-wavelength of the modulation should be commensurate with -the lattice, or $q_*\simeq0.328\,\A^{-1}$ \cite{meng_imaging_2013}. In between +the lattice, or $q_*\simeq0.328\,\A^{-1}$ \cite{meng_imaging_2013, +broholm_magnetic_1991, wiebe_gapped_2007, bourdarot_precise_2010}. In between these two regimes, the ordering wavevector should shrink by jumping between ever-closer commensurate values in the style of the devil's staircase \cite{bak_commensurate_1982}. This motivates future \rus\ experiments done at pressure, where the depth of the cusp in the $\Bog$ stiffness should deepen (perhaps with these commensurability jumps) at low pressure and approach zero like $q_*^4\sim(c_\perp/2D_\perp)^2$ near the Lifshitz point. The presence of -spatial commensurability is not expected to modify the critical behavior otherwise -\cite{garel_commensurability_1976}. +spatial commensurability is not expected to modify the critical behavior +otherwise \cite{garel_commensurability_1976}. There are two apparent discrepancies between the orthorhombic strain in the phase diagram presented by \cite{choi_pressure-induced_2018} and that predicted |