Physical Review B最新文献

{"title":"Model of a non-Fermi liquid with power-law resistivity: Strange metal with a not-so-strange origin","authors":"Patrick A. Lee","doi":"10.1103/physrevb.110.l121110","DOIUrl":"https://doi.org/10.1103/physrevb.110.l121110","url":null,"abstract":"We construct a model that exhibits resistivity going as a power law in temperature <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>T</mi></math>, as <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>T</mi><mi>α</mi></msup></math> down to the lowest temperature. There is no residual resistivity because we assume the absence of disorder and momentum relaxation is due to umklapp scattering. Our model consists of a quantum spin liquid state with a spinon Fermi surface and a hole Fermi surface made out of doped holes. The key ingredient is a set of singular <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><msub><mi>k</mi><mi>F</mi></msub></mrow></math> modes living on a ring in momentum space. Depending on parameters, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>α</mi></math> may be unity (strange metal) or even smaller. The model may be applicable to a doped organic compound, which has been found to exhibit linear <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>T</mi></math> resistivity. We conclude that it is possible to obtain strange metal behavior starting with a model that is not so strange.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174546","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":"Transition between scattering regimes of two-dimensional electron transport","authors":"Philipp Heilmann, Pavlo V. Pyshkin, Björn Trauzettel","doi":"10.1103/physrevb.110.115420","DOIUrl":"https://doi.org/10.1103/physrevb.110.115420","url":null,"abstract":"We examine two-dimensional electron transport through a long narrow channel driven by an external electric field in the presence of diffusive boundary scattering. At zero temperature, we derive an analytical solution of the transition from ballistic to diffusive transport if we increase the bulk disorder strength. This crossover yields characteristic current density profiles. Furthermore, we illustrate the current density in the transition from ballistic to hydrodynamic transport. This corresponds to the Gurzhi effect in the resistivity. We also study the influence of finite temperature on current densities and average current in this system. In particular, we analyze how a particular scaling law of electron-electron scattering with respect to temperature affects the current along the channel.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231514","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":"Unexpected anisotropic compression-induced superconductivity in pristine 2H-MoTe2","authors":"Tao Lin, Run Lv, Qing Dong, Chenyi Li, Bo Liu, Ran Liu, Xiaoling Jing, Yuping Sun, Quanjun Li, Wenjian Lu, Bingbing Liu","doi":"10.1103/physrevb.110.104511","DOIUrl":"https://doi.org/10.1103/physrevb.110.104511","url":null,"abstract":"High-pressure application is crucial for shaping material properties and revealing novel phenomena. Materials undergo more unpredictable transitions in their crystal and electronic structures under nonhydrostatic/isotropic pressures than under hydrostatic conditions. However, limited knowledge regarding this behavior exists due to a scarcity of relevant studies. In this study, we systematically investigated the evolution of the structure and electronic states of pristine <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mi>H</mi><mtext>-MoT</mtext><msub><mi mathvariant=\"normal\">e</mi><mn>2</mn></msub></mrow></math> in anisotropic pressure environments. Surprisingly, we observed anisotropic compression-induced superconductivity in this material, a phenomenon that is absent in quasihydrostatic environments. High-pressure x-ray diffraction and Raman spectroscopy measurements showed no structural phase transitions; however, an anomalous compressive behavior was observed along the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>c</mi></math> axis. An anisotropic pressure model was proposed based on experimental conditions. First-principles calculations revealed that a strengthened anisotropic compression effect could enhance electron-phonon coupling by increasing the density of states on the Fermi level and softening the phonon modes, contributing to the emergence of superconductivity in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mi>H</mi><mtext>-MoT</mtext><msub><mi mathvariant=\"normal\">e</mi><mn>2</mn></msub></mrow></math>. Our findings offer a route for inducing superconductivity, providing insights into the nature of superconductivity in transition metal dichalcogenides and other similar layered compounds under extreme conditions.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174589","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":"Generic topological criterion for flat bands in two dimensions","authors":"Alireza Parhizkar, Victor Galitski","doi":"10.1103/physrevb.110.l121111","DOIUrl":"https://doi.org/10.1103/physrevb.110.l121111","url":null,"abstract":"We show that the continuum limit of moiré graphene is described by a <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>(</mo><mn>2</mn><mo>+</mo><mn>1</mn><mo>)</mo></mrow></math>-dimensional field theory of Dirac fermions coupled to two classical vector fields: a periodic gauge and a spin field. We further show that the existence of a flat band implies an effective dimensional reduction, where the time dimension is “removed.” The resulting two-dimensional Euclidean theory contains the chiral anomaly. The associated Atiyah-Singer index theorem provides a self-consistency condition for flat bands. In the Abelian limit, where the spin field is disregarded, we reproduce a periodic series of quantized magic angles known to exist in twisted bilayer graphene in the chiral limit. However, the results are not exact. If the Abelian field has zero total flux, perfectly flat bands can not exist, because of the leakage of edge states into neighboring triangular patches with opposite field orientations. We demonstrate that the non-Abelian spin component can correct this and completely flatten the bands via an effective renormalization of the Abelian component into a configuration with a nonzero total flux. We present the <i>Abelianization</i> of the theory where the Abelianized flat band can be mapped to that of the lowest Landau level. We show that the Abelianization corrects the values of the magic angles consistent with numerical results. We also use this criterion to prove that an external magnetic field splits the series into pairs of magnetic field-dependent magic angles associated with flat moiré-Landau bands. The topological criterion and the Abelianization procedure provide a generic practical method for finding flat bands in a variety of material systems including but not limited to moiré bilayers.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231516","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":"Time reversal symmetry breaking and zero magnetic field Josephson diode effect in Dirac semimetal Cd3As2 mediated asymmetric SQUIDs","authors":"W. Yu, J. J. Cuozzo, K. Sapkota, E. Rossi, D. X. Rademacher, T. M. Nenoff, W. Pan","doi":"10.1103/physrevb.110.104510","DOIUrl":"https://doi.org/10.1103/physrevb.110.104510","url":null,"abstract":"A <i>zero-magnetic-field</i> Josephson diode effect (JDE) is observed in an asymmetric superconducting quantum interference device (SQUID) mediated by Dirac semimetal <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">C</mi><msub><mi mathvariant=\"normal\">d</mi><mn>3</mn></msub><mi mathvariant=\"normal\">A</mi><msub><mi mathvariant=\"normal\">s</mi><mn>2</mn></msub></mrow></math>. We argue that a phase coupling between the surface and bulk superconducting channels, a unique phenomenon recently identified in the observations of fractional Josephson effect and Leggett modes in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">C</mi><msub><mi mathvariant=\"normal\">d</mi><mn>3</mn></msub><mi mathvariant=\"normal\">A</mi><msub><mi mathvariant=\"normal\">s</mi><mn>2</mn></msub></mrow></math>, can break time reversal symmetry and therefore give rise to the zero-field JDE. Our results are anticipated to have important implications in superconducting electronic circuit applications.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174655","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":"Chern bands with higher-order Van Hove singularities on topological moiré surface states","authors":"Lakshmi Pullasseri, Luiz H. Santos","doi":"10.1103/physrevb.110.115125","DOIUrl":"https://doi.org/10.1103/physrevb.110.115125","url":null,"abstract":"In two-dimensional electronic lattices, changes in the topology of the Fermi surface (Lifshitz transitions) lead to Van Hove singularities characterized by a divergence in the electronic density of states. Van Hove singularities can enhance the effect of electronic interactions, providing a platform to explore novel correlated electronic states. In this work, we investigate the emergence of topological Chern bands on the surface of three-dimensional topological insulators, which host higher-order Van Hove singularities that are characterized by the power-law diverging density of states. These singularities can arise from the interplay between a time-reversal-breaking Zeeman field induced by proximity to a ferromagnetic insulator and a time-reversal-invariant moiré potential on the surface electrons, created by quintuple layer misalignment in a family of topological insulators such as <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Bi</mi><mn>2</mn></msub><msub><mi>Se</mi><mn>3</mn></msub></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Bi</mi><mn>2</mn></msub><msub><mi>Te</mi><mn>3</mn></msub></mrow></math>, which host a single surface Dirac fermion. We establish the onset of Chern bands near charge neutrality with Chern numbers <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>C</mi><mo>=</mo><mo>±</mo><mn>1</mn></mrow></math> that also possess a manifold of higher-order Van Hove singularities on the moiré Brillouin zone valleys controlled by the Zeeman and moiré potential energy scales, unveiling a platform to realize exotic Lifshitz transitions in topological bands. Furthermore, we show that the strong peaks in the density of states in the vicinity of Lifshitz transitions give rise to characteristic features in the low-temperature intrinsic anomalous Hall conductivity, yielding a path to probe Van Hove singularities in Chern bands through anomalous transport measurements.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174585","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":"Anyon condensation in string-net models","authors":"Chien-Hung Lin, Fiona J. Burnell","doi":"10.1103/physrevb.110.115127","DOIUrl":"https://doi.org/10.1103/physrevb.110.115127","url":null,"abstract":"We study the condensation of Abelian bosons in string-net models by constructing a family of Hamiltonians that can be tuned through any such transition. We show that these Hamiltonians admit two exactly solvable, string-net limits: one deep in the uncondensed phase, described by an initial, uncondensed string-net Hamiltonian, and one deep in the condensed phase, described by a final, condensed string-net model. We give a systematic description of the condensed string-net model in terms of the uncondensed string-net and the data associated with the condensing Abelian bosons. Specifically, if the uncondensed string-net is described by a fusion category <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"script\">C</mi></math>, we show how the string labels and fusion data of the fusion category <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mover accent=\"true\"><mi mathvariant=\"script\">C</mi><mo>̃</mo></mover></math> describing the condensed string-net can be obtained from that of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi mathvariant=\"script\">C</mi></math> and the data describing the string operators that create the condensing boson. This construction generalizes previous approaches to anyon condensation in string-nets by allowing the condensation of arbitrary Abelian bosons, including chiral bosons in string-nets constructed from, for example, Chern-Simons theories, which describe time-reversal invariant bilayer states. This gives a method for obtaining the full data for string-nets without explicit time-reversal symmetry from such bilayer models. We illustrate our approach with several examples.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231472","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":"Charge self-consistent density functional theory plus ghost rotationally invariant slave-boson theory for correlated materials","authors":"Tsung-Han Lee, Corey Melnick, Ran Adler, Xue Sun, Yongxin Yao, Nicola Lanatà, Gabriel Kotliar","doi":"10.1103/physrevb.110.115126","DOIUrl":"https://doi.org/10.1103/physrevb.110.115126","url":null,"abstract":"We present a charge self-consistent density functional theory combined with the ghost rotationally invariant slave-boson (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>DFT</mi><mo>+</mo><mi>gRISB</mi></math>) formalism for studying correlated materials. This method is applied to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>SrVO</mi><mn>3</mn></msub></math> and NiO, representing prototypical correlated metals and charge-transfer insulators. For <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>SrVO</mi><mn>3</mn></msub></math>, we demonstrate that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>DFT</mi><mo>+</mo><mi>gRISB</mi></math> yields an accurate equilibrium volume and effective mass close to experimentally observed values. Regarding NiO, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>DFT</mi><mo>+</mo><mi>gRISB</mi></math> enables the simultaneous description of charge-transfer and Mott-Hubbard bands, significantly enhancing the accuracy of the original <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>DFT</mi><mo>+</mo><mi>RISB</mi></math> approach. Furthermore, the calculated equilibrium volume and spectral function reasonably agree with experimental observations.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174586","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":"Gross-Neveu-Yukawa theory of SO(2N)→SO(N)×SO(N) spontaneous symmetry breaking","authors":"SangEun Han, Igor F. Herbut","doi":"10.1103/physrevb.110.125131","DOIUrl":"https://doi.org/10.1103/physrevb.110.125131","url":null,"abstract":"We construct and study the relativistic Gross-Neveu-Yukawa field theory for the &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mtext&gt;SO&lt;/mtext&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt; real symmetric second-rank tensor order parameter coupled to &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt; flavors of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;-component Majorana fermions in &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/math&gt; dimensions. Such a tensor order parameter unifies all Lorentz-invariant mass-gap orders for &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/math&gt; two-component Dirac fermions in two dimensions except for the &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mtext&gt;SO&lt;/mtext&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;-singlet anomalous quantum Hall state. The value &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt; corresponds to the canonical Gross-Neveu model. Within the leading-order &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mi&gt;ε&lt;/mi&gt;&lt;/math&gt;-expansion around the upper critical dimension of &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;, the field theory exhibits a critical fixed point in its renormalization group flow which describes spontaneous symmetry breaking to &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;mtext&gt;SO&lt;/mtext&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;mtext&gt;SO&lt;/mtext&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt; for the number of flavors of Majorana fermions higher than a critical value &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;≈&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;. For &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;, with &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;≈&lt;/mo&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;, the critical fixed point resides in the unstable region of the theory where the effective potential is unbounded from below, whereas for &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt; there is no real critical fixed point and the flow runs away. In either case, for &lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174591","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":"Chiral Stoner magnetism in Dirac bands","authors":"Zhiyu Dong, Leonid Levitov","doi":"10.1103/physrevb.110.104420","DOIUrl":"https://doi.org/10.1103/physrevb.110.104420","url":null,"abstract":"Stoner magnetism in bands endowed with Berry curvature is shown to be influenced by the coupling between spin-chirality density <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"bold-italic\">s</mi><mo>·</mo><mo>(</mo><msub><mi>∂</mi><mi>x</mi></msub><mi mathvariant=\"bold-italic\">s</mi><mo>×</mo><msub><mi>∂</mi><mi>y</mi></msub><mi mathvariant=\"bold-italic\">s</mi><mo>)</mo></mrow></math> and Berry's orbital magnetization. The key effect is that carriers moving in the presence of a spin texture see it as a source of a geometric magnetic field coupled to the carrier's orbital motion through a spin-dependent Aharonov-Bohm effect. This interaction was recently predicted to enable chiral magnons propagating along system boundaries. Here we show that it also favors chiral spin textures such as skyrmions—the topologically protected objects with particle-like properties, stabilized in the ground state. Unlike previously studied systems, here skyrmion textures can arise in the absence of microscopic spin-dependent interactions such as spin-orbit coupling or Zeeman coupling. The threshold for Stoner instability is found to soften, rendering chiral spin-ordered phases accessible under realistic conditions. We present a detailed analysis of the chiral effect for Bernal bilayer graphene and discuss the unique properties of skyrmion textures in graphene multilayers.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174659","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}