Physical Review B最新文献

{"title":"Influence of pressure on the properties of the multigap type-I superconductor BeAu","authors":"Rustem Khasanov, Riccardo Vocaturo, Oleg Janson, Andreas Koitzsch, Ritu Gupta, Debarchan Das, Nicola P. M. Casati, Maia G. Vergniory, Jeroen van den Brink, Eteri Svanidze","doi":"10.1103/physrevb.111.104507","DOIUrl":"https://doi.org/10.1103/physrevb.111.104507","url":null,"abstract":"We report on studies of the superconducting and normal-state properties of the noncentrosymmetric superconductor BeAu under hydrostatic pressure conditions. The room-temperature equation of state (EOS) reveals the values of the bulk modulus (B</a:mi>0</a:mn></a:msub></a:math>) and its first derivative (<b:math xmlns:b=\"http://www.w3.org/1998/Math/MathML\"><b:msubsup><b:mi>B</b:mi><b:mn>0</b:mn><b:mo>′</b:mo></b:msubsup></b:math>) at ambient pressure to be <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\"><c:mrow><c:msub><c:mi>B</c:mi><c:mn>0</c:mn></c:msub><c:mo>≃</c:mo><c:mn>133</c:mn><c:mspace width=\"0.28em\"/><c:mi>GPa</c:mi></c:mrow></c:math> and <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\"><e:mrow><e:msubsup><e:mi>B</e:mi><e:mn>0</e:mn><e:mo>′</e:mo></e:msubsup><e:mo>≃</e:mo><e:mn>30</e:mn></e:mrow></e:math>, respectively. Up to the highest pressures studied (<f:math xmlns:f=\"http://www.w3.org/1998/Math/MathML\"><f:mrow><f:mi>p</f:mi><f:mo>≃</f:mo><f:mn>2.2</f:mn><f:mspace width=\"0.28em\"/><f:mi>GPa</f:mi></f:mrow></f:math>), BeAu remains a multigap type-I superconductor. The analysis of <h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\"><h:mrow><h:msub><h:mi>B</h:mi><h:mi mathvariant=\"normal\">c</h:mi></h:msub><h:mrow><h:mo>(</h:mo><h:mi>T</h:mi><h:mo>,</h:mo><h:mi>p</h:mi><h:mo>)</h:mo></h:mrow></h:mrow></h:math> data within the self-consistent two-gap approach suggests the presence of two superconducting energy gaps, with the gap-to-<j:math xmlns:j=\"http://www.w3.org/1998/Math/MathML\"><j:msub><j:mi>T</j:mi><j:mi mathvariant=\"normal\">c</j:mi></j:msub></j:math> ratios <l:math xmlns:l=\"http://www.w3.org/1998/Math/MathML\"><l:mrow><l:msub><l:mi mathvariant=\"normal\">Δ</l:mi><l:mn>1</l:mn></l:msub><l:mo>/</l:mo><l:msub><l:mi>k</l:mi><l:mi mathvariant=\"normal\">B</l:mi></l:msub><l:msub><l:mi>T</l:mi><l:mi mathvariant=\"normal\">c</l:mi></l:msub><l:mo>∼</l:mo><l:mn>2.3</l:mn></l:mrow></l:math> and <p:math xmlns:p=\"http://www.w3.org/1998/Math/MathML\"><p:mrow><p:msub><p:mi mathvariant=\"normal\">Δ</p:mi><p:mn>2</p:mn></p:msub><p:mo>/</p:mo><p:msub><p:mi>k</p:mi><p:mi mathvariant=\"normal\">B</p:mi></p:msub><p:msub><p:mi>T</p:mi><p:mi mathvariant=\"normal\">c</p:mi></p:msub><p:mo>∼</p:mo><p:mn>1.1</p:mn></p:mrow></p:math> for the larger and smaller gaps, respectively [<t:math xmlns:t=\"http://www.w3.org/1998/Math/MathML\"><t:mrow><t:mi mathvariant=\"normal\">Δ</t:mi><t:mo>=</t:mo><t:mi mathvariant=\"normal\">Δ</t:mi><t:mo>(</t:mo><t:mn>0</t:mn><t:mo>)</t:mo></t:mrow></t:math> is the zero-temperature value of the gap and <w:math xmlns:w=\"http://www.w3.org/1998/Math/MathML\"><w:msub><w:mi>k</w:mi><w:mi mathvariant=\"normal\">B</w:mi></w:msub></w:math> is the Boltzmann constant]. With increasing pressure, <y:math xmlns:y=\"http://www.w3.org/1998/Math/MathML\"><y:mrow><y:msub><y:mi mathvariant=\"normal\">Δ</y:mi><y:mn>1</y:mn></y:msub><y:mo>/</y:mo><y:msub><y:mi>k</y:mi><y:mi mathvariant=\"normal\">B</y:mi></y:msub><y:msub><y:mi>T</y:mi><y:mi mathvariant=\"normal\">c</y:m","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"124 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Competing ordinary and Hanle magnetoresistance in Pt and Ti thin films","authors":"Sebastian Sailler, Giacomo Sala, Denise Reustlen, Richard Schlitz, Min-Gu Kang, Pietro Gambardella, Sebastian T. B. Goennenwein, Michaela Lammel","doi":"10.1103/physrevb.111.104421","DOIUrl":"https://doi.org/10.1103/physrevb.111.104421","url":null,"abstract":"One of the key elements in spintronics research is the spin Hall effect, allowing to generate spin currents from charge currents. A large spin Hall effect is observed in materials with strong spin-orbit coupling, e.g., Pt. Recent research suggests the existence of an orbital Hall effect, the orbital analog to the spin Hall effect, which also arises in weakly spin-orbit-coupled materials like Ti, Mn, or Cr. In Pt both effects are predicted to coexist. In any of these materials, a magnetic field perpendicular to the spin or orbital accumulation leads to additional Hanle dephasing and thereby the Hanle magnetoresistance (MR). To reveal the MR behavior of a material with both spin and orbital Hall effect, we first study the MR of Pt thin films over a wide range of thicknesses. Careful evaluation shows that the MR of our textured samples is dominated by the ordinary MR rather than by the Hanle effect. We analyze the intrinsic properties of Pt films deposited by different groups and show that next to the resistivity also the structural properties of the film influence which MR dominates. We further show that this correlation can be found in both spin Hall active materials like Pt and orbital Hall active materials, like Ti. For both materials, we find a large Hanle MR for the samples without apparent structural order, whereas the ordinary MR dominates in the crystalline samples. We then provide a set of rules to distinguish between the ordinary and the Hanle MR. We suggest that in all materials with a spin or orbital Hall effect the Hanle MR and the ordinary MR coexist and the purity, crystallinity, and electronic structure of the thin film determine the dominating effect. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"9 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green's function approach to Josephson dot dynamics and application to quantum Mpemba effects","authors":"Kateryna Zatsarynna, Andrea Nava, Reinhold Egger, Alex Zazunov","doi":"10.1103/physrevb.111.104506","DOIUrl":"https://doi.org/10.1103/physrevb.111.104506","url":null,"abstract":"We develop a Green's function approach for the nonequilibrium dynamics of multilevel quantum dots coupled to multiple fermionic reservoirs in the presence of a bosonic environment. Our theory is simpler than the Keldysh approach and goes beyond scattering state constructions. In concrete terms, we study Josephson junctions containing a quantum dot and coupled to an electromagnetic environment. In the dot region, spin-orbit interactions, a Zeeman field, and in principle Coulomb interactions can also be included. We then study quantum Mpemba effects, assuming that the average phase difference across the Josephson junction is subject to a rapid quench. For a short single-channel junction, we show that both types of quantum Mpemba effects allowed in open quantum systems can occur. We also study an intermediate-length junction, where spin-orbit interactions and a Zeeman field are included. Again quantum Mpemba effects are predicted. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"197 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muon spectroscopy investigation of anomalous dynamic magnetism in NiI2","authors":"T. L. Breeze, B. M. Huddart, A. Hernández-Melián, N. P. Bentley, D. A. Mayoh, G. D. A. Wood, G. Balakrishnan, J. Wilkinson, F. L. Pratt, T. J. Hicken, S. J. Clark, T. Lancaster","doi":"10.1103/physrevb.111.104420","DOIUrl":"https://doi.org/10.1103/physrevb.111.104420","url":null,"abstract":"We present the results of muon-spin relaxation (μ</a:mi>+</a:mo></a:msup>SR</a:mi></a:mrow></a:math>) measurements of the van der Waals magnet <b:math xmlns:b=\"http://www.w3.org/1998/Math/MathML\"><b:msub><b:mi>NiI</b:mi><b:mn>2</b:mn></b:msub></b:math>, which probe magnetic phase transitions at <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\"><c:mrow><c:msub><c:mi>T</c:mi><c:mrow><c:mi mathvariant=\"normal\">N</c:mi><c:mn>1</c:mn></c:mrow></c:msub><c:mo>=</c:mo><c:mn>73</c:mn><c:mspace width=\"0.16em\"/><c:mi mathvariant=\"normal\">K</c:mi></c:mrow></c:math> and <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\"><g:mrow><g:msub><g:mi>T</g:mi><g:mrow><g:mi mathvariant=\"normal\">N</g:mi><g:mn>2</g:mn></g:mrow></g:msub><g:mo>=</g:mo><g:mn>62</g:mn><g:mspace width=\"0.16em\"/><g:mi mathvariant=\"normal\">K</g:mi></g:mrow></g:math>. Supporting density functional theory (DFT) calculations allow the determination of a single muon stopping site whose magnetic environment is consistent with the proposed ground-state magnetic structure. <k:math xmlns:k=\"http://www.w3.org/1998/Math/MathML\"><k:mrow><k:msup><k:mi>μ</k:mi><k:mo>+</k:mo></k:msup><k:mi>SR</k:mi></k:mrow></k:math> measurements of the dynamics reveal behavior consistent with spin-wave excitations below <l:math xmlns:l=\"http://www.w3.org/1998/Math/MathML\"><l:msub><l:mi>T</l:mi><l:mrow><l:mi mathvariant=\"normal\">N</l:mi><l:mn>2</l:mn></l:mrow></l:msub></l:math>. In the region <n:math xmlns:n=\"http://www.w3.org/1998/Math/MathML\"><n:mrow><n:msub><n:mi>T</n:mi><n:mrow><n:mi mathvariant=\"normal\">N</n:mi><n:mn>2</n:mn></n:mrow></n:msub><n:mo>&lt;</n:mo><n:mi>T</n:mi><n:mo>&lt;</n:mo><n:msub><n:mi>T</n:mi><n:mrow><n:mi mathvariant=\"normal\">N</n:mi><n:mn>1</n:mn></n:mrow></n:msub></n:mrow></n:math> the character of the dynamics changes qualitatively, resulting in an unusual region of temperature-independent fluctuations. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"25 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impurity strength–temperature phase diagram with phase crystals and competing time-reversal symmetry breaking states in nodal d -wave superconductors","authors":"K. M. Seja, N. Wall-Wennerdal, T. Löfwander, A. M. Black-Schaffer, M. Fogelström, P. Holmvall","doi":"10.1103/physrevb.111.094513","DOIUrl":"https://doi.org/10.1103/physrevb.111.094513","url":null,"abstract":"Phase crystals are a class of nonuniform superconducting ground states characterized by spontaneous phase gradients of the superconducting order parameter. These phase gradients nonlocally drive periodic currents and magnetic fields, thus breaking both time-reversal symmetry and continuous translational symmetry. The phase crystal instability is generally triggered by negative and inhomogeneous superfluid stiffness. Several scenarios have been identified that can realize phase crystals, especially flat bands at specific edges of unconventional nodal superconductors. Motivated by omnipresent disorder in all materials, we employ the t</a:mi></a:math>-matrix approach within the quasiclassical theory of superconductivity to study the emergence of phase crystals at edges of a nodal <b:math xmlns:b=\"http://www.w3.org/1998/Math/MathML\"><b:mi>d</b:mi></b:math>-wave superconductor. We quantify the full phase diagram as a function of the impurity scattering energy and the temperature, with full self-consistency in the impurity self energies, the superconducting order parameter, and the vector potential. We find that the phase crystal survives even up to <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\"><c:mrow><c:mo>∼</c:mo><c:mn>40</c:mn><c:mo>–</c:mo><c:mn>50</c:mn><c:mo>%</c:mo></c:mrow></c:math> of the superconducting critical impurity strength in both the Born and unitary scattering limits. Finally, we show how mesoscopic finite-size effects induce a competition with a state still breaking time-reversal symmetry but with translationally invariant edge currents. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"54 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143618782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unconventional gap structures and the intermediate mixed state: A vortex lattice study of the noncentrosymmetric superconductor BiPd","authors":"A. S. Cameron, L. Lemberger, R. Riyat, A. T. Holmes, Y. S. Yerin, A. D. Hillier, B. Joshi, S. Ramakrishnan, J. Gavilano, C. D. Dewhurst, E. M. Forgan, E. Blackburn","doi":"10.1103/physrevb.111.094514","DOIUrl":"https://doi.org/10.1103/physrevb.111.094514","url":null,"abstract":"We report on neutron scattering measurements on the vortex lattice of the noncentrosymmetric superconductor BiPd. We observe the existence of the intermediate mixed state, a region where Meissner and vortex lattice phases coexist, which is a feature of low κ</a:mi></a:math> type-II superconductors. Following this, we obtain an estimate of the value of <b:math xmlns:b=\"http://www.w3.org/1998/Math/MathML\"><b:mi>κ</b:mi></b:math> using the extended London model. Finally, we find that the temperature dependence of the vortex lattice form factor fits well to a model designed to describe singlet-triplet mixing in noncentrosymmetric superconductors, which may shed light on the question of the gap structure in BiPd. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"54 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143618713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic ground state of the dimer-based hexagonal perovskite Ba3ZnRu2O9","authors":"S. Hayashida, H. Gretarsson, P. Puphal, M. Isobe, E. Goering, Y. Matsumoto, J. Nuss, H. Takagi, M. Hepting, B. Keimer","doi":"10.1103/physrevb.111.104418","DOIUrl":"https://doi.org/10.1103/physrevb.111.104418","url":null,"abstract":"We investigate the magnetic ground state of single crystals of the ruthenium-dimer-based hexagonal perovskite Ba</a:mi>3</a:mn></a:msub>ZnRu</a:mi>2</a:mn></a:msub>O</a:mi>9</a:mn></a:msub></a:mrow></a:math> using magnetic susceptibility and resonant inelastic x-ray scattering (RIXS) measurements. While a previous study on powder samples exhibited intriguing magnetic behavior, questions about whether the spin state within a <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\"><c:mrow><c:msub><c:mi>Ru</c:mi><c:mn>2</c:mn></c:msub><c:msub><c:mi mathvariant=\"normal\">O</c:mi><c:mn>9</c:mn></c:msub></c:mrow></c:math> dimer is a conventional <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\"><e:mrow><e:mi>S</e:mi><e:mo>=</e:mo><e:mn>3</e:mn><e:mo>/</e:mo><e:mn>2</e:mn></e:mrow></e:math> dimer or an orbital-selective <f:math xmlns:f=\"http://www.w3.org/1998/Math/MathML\"><f:mrow><f:mi>S</f:mi><f:mo>=</f:mo><f:mn>1</f:mn></f:mrow></f:math> dimer were raised. The RIXS spectra reveal magnetic excitations from Hund's intraionic multiplet and intradimer spin-triplet transitions. The observed transition energies of the Hund's intraionic multiplets align with the <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\"><g:mrow><g:mi>S</g:mi><g:mo>=</g:mo><g:mn>3</g:mn><g:mo>/</g:mo><g:mn>2</g:mn></g:mrow></g:math> ground state, contrasting with the theoretically proposed orbital-selective <h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\"><h:mrow><h:mi>S</h:mi><h:mo>=</h:mo><h:mn>1</h:mn></h:mrow></h:math> dimer state. High-temperature magnetic susceptibility analysis confirms the realization of the spin <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\"><i:mrow><i:mi>S</i:mi><i:mo>=</i:mo><i:mn>3</i:mn><i:mo>/</i:mo><i:mn>2</i:mn></i:mrow></i:math> dimer state, and the extracted intradimer coupling is consistent with the spin-triplet transition energy observed in the RIXS spectra. These results highlights the ability of “spectroscopic fingerprinting” by RIXS to determine the magnetic ground states of complex materials. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"4 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143618783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissipative spin-orbit coupled vortex rings in vector exciton-polariton condensates","authors":"C. B. Tabi, E. B. Madimabe, L. Tiam Megne, E. Wamba, T. C. Kofané","doi":"10.1103/physrevb.111.104307","DOIUrl":"https://doi.org/10.1103/physrevb.111.104307","url":null,"abstract":"Exciton-polariton condensates are explored using coupled driven-dissipative Gross-Pitaevskii equations under the Keeling-Berloff approximation in the presence of photonic spin-orbit coupling (SOC). An extended dissipative variational approximation method uses analytical expressions for coupled vortex ring solitons as minimizing functions of a generalized Lagrangian framework. The results reveal that the amplitudes of the vortices are linked to losses and gain, while the topological charges of the vortices are tied to the width of the vortex rings. Numerically, using the proposed solution as initial conditions, the emergence of even-numbered multilobed rings takes place as the topological charges of the seeded vortices are increased. The analytical results are then confronted by a detailed numerical analysis that further elucidates the rich vortex dynamics inferred by SOC and other combinations of various system parameters. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"56 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143618780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral function of a bipolaron coupled to dispersive optical phonons","authors":"K. Kovač, J. Bonča","doi":"10.1103/physrevb.111.115133","DOIUrl":"https://doi.org/10.1103/physrevb.111.115133","url":null,"abstract":"Using an efficient variational exact diagonalization method, we computed the electron removal spectral function within the framework of the Holstein-Hubbard model containing two electrons with opposite spins coupled to dispersive quantum optical phonons. We focus on how the interplay between the electron-phonon coupling and on-site Coulomb repulsion shapes the spectral function, a quantity directly relevant to angle-resolved photoemission spectroscopy (ARPES). Tuning the strengths of the electron-phonon coupling and the Hubbard interaction allows us to examine the evolution of the spectral properties of the system as it crosses over from a bound bipolaron to separate polarons. We find that phonon dispersion plays an important role: It substantially redistributes the spectral weight across the low- and the high-energy features and controls the emergence and the structure of distinct multiphonon continua. In regimes of strong electron-phonon coupling and low Coulomb repulsion, the spectral function exhibits a broad distribution reflecting bound bipolaronic states. Increasing the Coulomb repulsion weakens bipolaron binding, shifts the primary quasiparticle peak closer to polaronic behavior and confines the spectral weight near the Brillouin-zone center. Our results provide a framework for interpreting ARPES measurements in systems where phonon–mediated attraction competes with direct Coulomb repulsion. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"9 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143608341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harris-Luck criterion in the plateau transition of the integer quantum Hall effect","authors":"H. Topchyan, W. Nuding, A. Klümper, A. Sedrakyan","doi":"10.1103/physrevb.111.l100201","DOIUrl":"https://doi.org/10.1103/physrevb.111.l100201","url":null,"abstract":"The Harris criterion imposes a constraint on the critical behavior of a system upon introduction of new disorder, based on its dimension d</a:mi></a:math> and localization length exponent <b:math xmlns:b=\"http://www.w3.org/1998/Math/MathML\"><b:mi>ν</b:mi></b:math>. It states that the new disorder can be relevant only if <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\"><c:mrow><c:mi>d</c:mi><c:mi>ν</c:mi><c:mo>&lt;</c:mo><c:mn>2</c:mn></c:mrow></c:math>. We analyze the applicability of the Harris criterion to the GKNS network disorder formulated in the paper [I. A. Gruzberg, A. Klümper, W. Nuding, and A. Sedrakyan, ] and show that the fluctuations of the geometry are relevant despite <d:math xmlns:d=\"http://www.w3.org/1998/Math/MathML\"><d:mrow><d:mi>d</d:mi><d:mi>ν</d:mi><d:mo>&gt;</d:mo><d:mn>2</d:mn></d:mrow></d:math>, implying that the Harris criterion should be modified. We have observed that the fluctuations of the critical point in different quenched configurations of disordered network blocks is of order <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\"><e:msup><e:mi>L</e:mi><e:mn>0</e:mn></e:msup></e:math>, i.e., it does not depend on block size <f:math xmlns:f=\"http://www.w3.org/1998/Math/MathML\"><f:mi>L</f:mi></f:math> in contrast to the expectation based on the Harris criterion that they should decrease as <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\"><g:msup><g:mi>L</g:mi><g:mrow><g:mo>−</g:mo><g:mi>d</g:mi><g:mo>/</g:mo><g:mn>2</g:mn></g:mrow></g:msup></g:math> according to the central limit theorem. Since <h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\"><h:mrow><h:msup><h:mi>L</h:mi><h:mn>0</h:mn></h:msup><h:mo>&gt;</h:mo><h:mrow><h:mo>(</h:mo><h:mi>x</h:mi><h:mo>−</h:mo><h:msub><h:mi>x</h:mi><h:mi>c</h:mi></h:msub><h:mo>)</h:mo></h:mrow></h:mrow></h:math> is always satisfied near the critical point, the mentioned network disorder is relevant and the critical indices of the system can be changed. We have also shown that the GKNS disordered network is fundamentally different from Voronoi-Delaunay and dynamically triangulated random lattices: The probability of higher connectivity in the GKNS network decreases in a power law as opposed to an exponential, indicating that we are dealing with a “scale-free” network, such as the internet, protein-protein interactions, etc. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":"16 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143608342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}