Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.045143
Loïc Herviou, Frédéric Mila
We numerically investigate the guiding center structure factors of several states in the Read-Rezayi family. Using exact diagonalizations on the torus and density matrix renormalization group on an infinite cylinder, we test a conjecture proposed in Can et al. [Phys. Rev. Lett.113, 046803 (2014)] for the and Read-Rezayi states. Furthermore, we discuss the strong finite-size effects present in numerically accessible wavefunctions, and provide a simple recipe to minimize them on manifolds where non-Abelian theories have topological degeneracies.
我们用数值方法研究了Read-Rezayi家族中几个状态的指导中心结构因子。利用环上的精确对角化和无限圆柱体上的密度矩阵重正化群，我们检验了 Can 等人[Phys. Rev. Lett. 113, 046803 (2014)]针对 ν=35 和 ν=46 Read-Rezayi 状态提出的猜想。此外，我们还讨论了数值波函数中存在的强烈的有限大小效应，并提供了一个简单的方法，在非阿贝尔理论具有拓扑退行性的流形上最小化这些效应。
{"title":"Numerical investigation of the structure factors of the Read-Rezayi series","authors":"Loïc Herviou, Frédéric Mila","doi":"10.1103/physrevb.110.045143","DOIUrl":"https://doi.org/10.1103/physrevb.110.045143","url":null,"abstract":"We numerically investigate the guiding center structure factors of several states in the Read-Rezayi family. Using exact diagonalizations on the torus and density matrix renormalization group on an infinite cylinder, we test a conjecture proposed in Can <i>et al.</i> [<span>Phys. Rev. Lett.</span> <b>113</b>, 046803 (2014)] for the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>ν</mi><mo>=</mo><mfrac><mn>3</mn><mn>5</mn></mfrac></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>ν</mi><mo>=</mo><mfrac><mn>4</mn><mn>6</mn></mfrac></mrow></math> Read-Rezayi states. Furthermore, we discuss the strong finite-size effects present in numerically accessible wavefunctions, and provide a simple recipe to minimize them on manifolds where non-Abelian theories have topological degeneracies.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750278","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}
We present a comprehensive Fermi liquid description for thermoelectric transport and current noise, applicable to multilevel quantum dots (QD) and magnetic alloys (MA) without electron-hole or time-reversal symmetry. Our formulation for the low-energy transport is based on an Anderson model with discrete impurity levels, and is asymptotically exact at low energies, up to the next-leading order terms in power expansions with respect to temperature and bias voltage . The expansion coefficients can be expressed in terms of the Fermi liquid parameters, which include the three-body correlation functions defined with respect to the equilibrium ground state in addition to the linear susceptibilities and the occupation number of impurity electrons. We apply this formulation to the symmetric QD and MA, and calculate the correlation functions for and 6, using numerical renormalization group approach. The three-body correlations are shown to be determined by a single parameter over a wide range of electron fillings for strong Coulomb interactions , and they also exhibit the plateau structures due to the Kondo effects at integer values of . We find that the Lorenz number for QD and MA, defined as the ratio of the thermal conductivity to the electrical conductivity , deviates from the universal Wiedemann-Franz value as the temperature increases from , showing the
{"title":"Thermoelectric transport and current noise through a multilevel Anderson impurity: Three-body Fermi liquid corrections in quantum dots and magnetic alloys","authors":"Yoshimichi Teratani, Kazuhiko Tsutsumi, Kaiji Motoyama, Rui Sakano, Akira Oguri","doi":"10.1103/physrevb.110.035308","DOIUrl":"https://doi.org/10.1103/physrevb.110.035308","url":null,"abstract":"We present a comprehensive Fermi liquid description for thermoelectric transport and current noise, applicable to multilevel quantum dots (QD) and magnetic alloys (MA) without electron-hole or time-reversal symmetry. Our formulation for the low-energy transport is based on an Anderson model with <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>N</mi></math> discrete impurity levels, and is asymptotically exact at low energies, up to the next-leading order terms in power expansions with respect to temperature <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>T</mi></math> and bias voltage <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>e</mi><mi>V</mi></mrow></math>. The expansion coefficients can be expressed in terms of the Fermi liquid parameters, which include the three-body correlation functions defined with respect to the equilibrium ground state in addition to the linear susceptibilities and the occupation number <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msubsup><mi>N</mi><mi>d</mi><mrow></mrow></msubsup></math> of impurity electrons. We apply this formulation to the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>SU</mi><mo>(</mo><mi>N</mi><mo>)</mo></mrow></math> symmetric QD and MA, and calculate the correlation functions for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>N</mi><mo>=</mo><mn>4</mn></mrow></math> and 6, using numerical renormalization group approach. The three-body correlations are shown to be determined by a single parameter over a wide range of electron fillings <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1</mn><mo>≲</mo><msubsup><mi>N</mi><mi>d</mi><mrow></mrow></msubsup><mo>≲</mo><mi>N</mi><mo>−</mo><mn>1</mn></mrow></math> for strong Coulomb interactions <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>U</mi></math>, and they also exhibit the plateau structures due to the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>SU</mi><mo>(</mo><mi>N</mi><mo>)</mo></mrow></math> Kondo effects at integer values of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msubsup><mi>N</mi><mi>d</mi><mrow></mrow></msubsup></math>. We find that the Lorenz number <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>L</mi><mo>=</mo><mi>κ</mi><mo>/</mo><mo>(</mo><mi>T</mi><mi>σ</mi><mo>)</mo></mrow></math> for QD and MA, defined as the ratio of the thermal conductivity <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>κ</mi></math> to the electrical conductivity <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>σ</mi></math>, deviates from the universal Wiedemann-Franz value <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msup><mi>π</mi><mn>2</mn></msup><mo>/</mo><mrow><mo>(</mo><mn>3</mn><msup><mi>e</mi><mn>2</mn></msup><mo>)</mo></mrow></mrow></math> as the temperature increases from <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>T</mi><mo>=</mo><mn>0</mn></mrow></math>, showing the <math xmlns=\"http://www.w3.org/1998/Math/MathM","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141764011","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}
Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.035425
Roman Ya. Kezerashvili, Shalva M. Tsiklauri, Anastasia Spiridonova
We predict the formation of intravalley and intervalley controllable trions in buckled two-dimensional (2D) materials such as silicene, germanene, and stanene monolayers in an external electric field. A study is performed within the framework of a nonrelativistic potential model using the method of hyperspherical harmonics (HH). We solve the three-body Schrödinger equation with the Rytova-Keldysh potential by expanding the wave functions of a trion in terms of the HH. A resultant system of coupled differential equations is solved numerically. Controllable ground-state energies of intravalley and intervalley trions by the external electric field are presented. The dependencies of the binding energy (BE) of trions in silicene, germanene, and stanene as a function of the electric field are qualitatively similar. BEs of trions formed by and excitons have a non-negligible difference that increases slightly as the electric field increases. It is demonstrated that trion BEs can be controlled by the external electric field, and the dielectric environment has a significant effect on the trion BE. The capability to control the BE and compactness of trions in buckled 2D materials by an external electric field suggests a possible trions crystallization in Xenes.
我们预测了硅烯、锗烯和链烷烯单层等降压二维（2D）材料在外加电场中形成的谷内和谷间可控三离子。研究在非相对论势模型的框架内使用超球谐波（HH）方法进行。我们利用 Rytova-Keldysh 势，通过以 HH 展开三元体的波函数来求解三体薛定谔方程。我们对由此产生的耦合微分方程系统进行了数值求解。提出了通过外部电场控制谷内和谷间三离子的基态能量。硅烯、锗烯和链烷烯中三离子的结合能（BE）与电场的函数关系在本质上是相似的。由 A 和 B 激子形成的三离子结合能具有不可忽略的差异，并随着电场的增加而略有增加。实验证明，三离子的 BE 可由外部电场控制，而电介质环境对三离子的 BE 有显著影响。通过外电场控制屈曲二维材料中三元子的BE和致密性的能力表明，三元子可能在氙中结晶。
{"title":"Controllable trions in buckled two-dimensional materials","authors":"Roman Ya. Kezerashvili, Shalva M. Tsiklauri, Anastasia Spiridonova","doi":"10.1103/physrevb.110.035425","DOIUrl":"https://doi.org/10.1103/physrevb.110.035425","url":null,"abstract":"We predict the formation of intravalley and intervalley controllable trions in buckled two-dimensional (2D) materials such as silicene, germanene, and stanene monolayers in an external electric field. A study is performed within the framework of a nonrelativistic potential model using the method of hyperspherical harmonics (HH). We solve the three-body Schrödinger equation with the Rytova-Keldysh potential by expanding the wave functions of a trion in terms of the HH. A resultant system of coupled differential equations is solved numerically. Controllable ground-state energies of intravalley and intervalley trions by the external electric field are presented. The dependencies of the binding energy (BE) of trions in silicene, germanene, and stanene as a function of the electric field are qualitatively similar. BEs of trions formed by <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>A</mi></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>B</mi></math> excitons have a non-negligible difference that increases slightly as the electric field increases. It is demonstrated that trion BEs can be controlled by the external electric field, and the dielectric environment has a significant effect on the trion BE. The capability to control the BE and compactness of trions in buckled 2D materials by an external electric field suggests a possible trions crystallization in Xenes.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750275","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}
Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.024426
Shuchen Li, Jonathan Gibbons, Stasiu Chyczewski, Zetai Liu, Hsu-Chih Ni, Jiangchao Qian, Jian-Min Zuo, Jun-Fei Zheng, Wenjuan Zhu, Axel Hoffmann
Materials with strong spin-orbit coupling and low crystalline symmetry are promising for generating large unconventional spin-orbit torques (SOTs), such as in-plane fieldlike (FL) torques and out-of-plane dampinglike (DL) torques, which can effectively manipulate and deterministically switch an out-of-plane magnetization without the need for additional external in-plane magnetic fields. Here, we report SOTs generated by magnetron-sputtered /Permalloy (Py; )/MgO heterostructures using both spin-torque ferromagnetic resonance (ST-FMR) and second harmonic Hall measurements. We observed unconventional FL and DL torques in our samples due to spins polarized normal to the interface of and Py layers, and studied the influence of crystallographic order and layer thickness on the SOTs. By comparing the Raman spectra of samples prepared in different ways, we found a tensile strain in sputtered films, which might further enhance the generation of unconventional torques by reducing the symmetry of .
{"title":"Unconventional spin-orbit torques from sputtered MoTe2 films","authors":"Shuchen Li, Jonathan Gibbons, Stasiu Chyczewski, Zetai Liu, Hsu-Chih Ni, Jiangchao Qian, Jian-Min Zuo, Jun-Fei Zheng, Wenjuan Zhu, Axel Hoffmann","doi":"10.1103/physrevb.110.024426","DOIUrl":"https://doi.org/10.1103/physrevb.110.024426","url":null,"abstract":"Materials with strong spin-orbit coupling and low crystalline symmetry are promising for generating large unconventional spin-orbit torques (SOTs), such as in-plane fieldlike (FL) torques and out-of-plane dampinglike (DL) torques, which can effectively manipulate and deterministically switch an out-of-plane magnetization without the need for additional external in-plane magnetic fields. Here, we report SOTs generated by magnetron-sputtered <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1</mn><msup><mi>T</mi><mo>′</mo></msup><mspace width=\"4pt\"></mspace><msub><mi>MoTe</mi><mn>2</mn></msub></mrow></math>/Permalloy (Py; <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Ni</mi><mn>80</mn></msub><msub><mi>Fe</mi><mn>20</mn></msub></mrow></math>)/MgO heterostructures using both spin-torque ferromagnetic resonance (ST-FMR) and second harmonic Hall measurements. We observed unconventional FL and DL torques in our samples due to spins polarized normal to the interface of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>MoTe</mi><mn>2</mn></msub></math> and Py layers, and studied the influence of crystallographic order and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>MoTe</mi><mn>2</mn></msub></math> layer thickness on the SOTs. By comparing the Raman spectra of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1</mn><msup><mi>T</mi><mo>′</mo></msup><mspace width=\"4pt\"></mspace><msub><mi>MoTe</mi><mn>2</mn></msub></mrow></math> samples prepared in different ways, we found a tensile strain in sputtered <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>MoTe</mi><mn>2</mn></msub></math> films, which might further enhance the generation of unconventional torques by reducing the symmetry of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1</mn><msup><mi>T</mi><mo>′</mo></msup><mspace width=\"4pt\"></mspace><msub><mi>MoTe</mi><mn>2</mn></msub></mrow></math>.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750335","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}
Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.035205
Jiacheng Wei, Zhonghao Xia, Yi Xia, Jiangang He
Lattice thermal conductivity () is a crucial characteristic of crystalline solids with significant implications for thermal management, energy conversion, and thermal barrier coating. The advancement of computational tools based on density functional theory (DFT) has enabled the effective utilization of phonon quasiparticle-based approaches to unravel the underlying physics of various crystalline systems. While the higher order of anharmonicity is commonly used for explaining extraordinary heat transfer behaviors in crystals, the impact of exchange-correlation (XC) functionals in DFT on describing anharmonicity has been largely overlooked. The XC functional is essential for determining the accuracy of DFT in describing interactions among electrons/ions in solids and molecules. However, most XC functionals in solid-state physics are primarily focused on computing the properties that only require small atomic displacements from the equilibrium (within the harmonic approximation), such as harmonic phonons and elastic constants, while anharmonicity involves larger atomic displacements. Therefore, it is more challenging for XC functionals to accurately describe atomic interactions at the anharmonicity level. In this study, we systematically investigate the room-temperature of 16 binary compounds with rocksalt and zinc-blende structures using various XC functionals such as local density approximation (LDA), Perdew-Burke-Ernzerhof (PBE), revised PBE for solid and surface (PBEsol), optimized B86b functional (optB86b), revised Tao-Perdew-Staroverov-Scuseria (revTPSS), strongly constrained and appropriately normed functional (SCAN), regularized SCAN (rSCAN), and regularized-restored SCAN () in combination with different perturbation orders, including phonon within harmonic approximation (HA) plus three-phonon scattering (), phonon calculated using self-consistent phonon theory (SCPH) plus three-phonon scattering (SCPH 3ph), and SCPH phonon plus three- and four-phonon scattering (SCPH 3,4ph). Our results show that the XC functional exhibits strong entanglement with perturbation order and the mean relative absolute error (MRAE) of the computed is strongly influenced by both the XC functional and perturbation order, leading to error c
{"title":"Hierarchy of exchange-correlation functionals in computing lattice thermal conductivities of rocksalt and zinc-blende semiconductors","authors":"Jiacheng Wei, Zhonghao Xia, Yi Xia, Jiangang He","doi":"10.1103/physrevb.110.035205","DOIUrl":"https://doi.org/10.1103/physrevb.110.035205","url":null,"abstract":"Lattice thermal conductivity (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>κ</mi><mi mathvariant=\"normal\">L</mi></msub></math>) is a crucial characteristic of crystalline solids with significant implications for thermal management, energy conversion, and thermal barrier coating. The advancement of computational tools based on density functional theory (DFT) has enabled the effective utilization of phonon quasiparticle-based approaches to unravel the underlying physics of various crystalline systems. While the higher order of anharmonicity is commonly used for explaining extraordinary heat transfer behaviors in crystals, the impact of exchange-correlation (XC) functionals in DFT on describing anharmonicity has been largely overlooked. The XC functional is essential for determining the accuracy of DFT in describing interactions among electrons/ions in solids and molecules. However, most XC functionals in solid-state physics are primarily focused on computing the properties that only require small atomic displacements from the equilibrium (within the harmonic approximation), such as harmonic phonons and elastic constants, while anharmonicity involves larger atomic displacements. Therefore, it is more challenging for XC functionals to accurately describe atomic interactions at the anharmonicity level. In this study, we systematically investigate the room-temperature <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>κ</mi><mi mathvariant=\"normal\">L</mi></msub></math> of 16 binary compounds with rocksalt and zinc-blende structures using various XC functionals such as local density approximation (LDA), Perdew-Burke-Ernzerhof (PBE), revised PBE for solid and surface (PBEsol), optimized B86b functional (optB86b), revised Tao-Perdew-Staroverov-Scuseria (revTPSS), strongly constrained and appropriately normed functional (SCAN), regularized SCAN (rSCAN), and regularized-restored SCAN (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msup><mrow><mi mathvariant=\"normal\">r</mi></mrow><mn>2</mn></msup><mi>SCAN</mi></mrow></math>) in combination with different perturbation orders, including phonon within harmonic approximation (HA) plus three-phonon scattering (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>HA</mi><mo>+</mo><mrow><mn>3</mn><mi>ph</mi></mrow></mrow></math>), phonon calculated using self-consistent phonon theory (SCPH) plus three-phonon scattering (SCPH <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mo>+</mo></math> 3ph), and SCPH phonon plus three- and four-phonon scattering (SCPH <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mo>+</mo></math> 3,4ph). Our results show that the XC functional exhibits strong entanglement with perturbation order and the mean relative absolute error (MRAE) of the computed <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>κ</mi><mi mathvariant=\"normal\">L</mi></msub></math> is strongly influenced by both the XC functional and perturbation order, leading to error c","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750339","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}
Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.024513
Xiaomeng Wang, Chi Ding, Qing Lu, Tianheng Huang, Yuhang Li, Junjie Wang, Yu Han, Dingyu Xing, Jian Sun
A major focus of current research on superconducting superhydrides is to achieve superconductivity at lower pressures, especially ambient pressure. Here we present the prediction of a class of high-temperature ternary hydrogen-rich superconductors, which are metastable at mild pressure and dynamically stable at ambient pressure using crystal structure searching. Our findings reveal the existence of a hexagonal compound with a superconducting of 61.5 K at ambient pressure, as estimated by electron-phonon coupling calculations. Interestingly, the H sites in materialize a breathing kagome network, equivalent to a triangular lattice of trimer plaquettes, which is entirely different from previously known hydrogen clathrate structures. By substituting Th with lanthanide elements, we discovered that and are also dynamically stable at 0 GPa, while and are dynamically stable at 10 and 15 GPa with high values of 63.9 and 65.9 K, respectively. Our results provide a system for superconducting hydrides and open a promising avenue for studying ambient pressure high-temperature superconductors.
{"title":"Prediction of ambient superconductivity in ternary thorium-silicon superhydrides with a breathing kagome lattice","authors":"Xiaomeng Wang, Chi Ding, Qing Lu, Tianheng Huang, Yuhang Li, Junjie Wang, Yu Han, Dingyu Xing, Jian Sun","doi":"10.1103/physrevb.110.024513","DOIUrl":"https://doi.org/10.1103/physrevb.110.024513","url":null,"abstract":"A major focus of current research on superconducting superhydrides is to achieve superconductivity at lower pressures, especially ambient pressure. Here we present the prediction of a class of high-temperature ternary hydrogen-rich superconductors, which are metastable at mild pressure and dynamically stable at ambient pressure using crystal structure searching. Our findings reveal the existence of a hexagonal <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>ThSi</mi><msub><mi mathvariant=\"normal\">H</mi><mn>7</mn></msub></mrow></math> compound with a superconducting <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>T</mi><mi mathvariant=\"normal\">c</mi></msub></math> of 61.5 K at ambient pressure, as estimated by electron-phonon coupling calculations. Interestingly, the H sites in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>ThSi</mi><msub><mi mathvariant=\"normal\">H</mi><mn>7</mn></msub></mrow></math> materialize a breathing kagome network, equivalent to a triangular lattice of trimer plaquettes, which is entirely different from previously known hydrogen clathrate structures. By substituting Th with lanthanide elements, we discovered that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>LaSi</mi><msub><mi mathvariant=\"normal\">H</mi><mn>7</mn></msub></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>CeSi</mi><msub><mi mathvariant=\"normal\">H</mi><mn>7</mn></msub></mrow></math> are also dynamically stable at 0 GPa, while <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>PrSi</mi><msub><mi mathvariant=\"normal\">H</mi><mn>7</mn></msub></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>NdSi</mi><msub><mi mathvariant=\"normal\">H</mi><mn>7</mn></msub></mrow></math> are dynamically stable at 10 and 15 GPa with high <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>T</mi><mi mathvariant=\"normal\">c</mi></msub></math> values of 63.9 and 65.9 K, respectively. Our results provide a system for superconducting hydrides and open a promising avenue for studying ambient pressure high-temperature superconductors.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141764108","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}
Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.045141
Marc Joosten, Michal Repisky, Marius Kadek, Pekka Pyykkö, Kenneth Ruud
We present an all-electron, four-component relativistic implementation of electric field gradients (EFGs) at the nuclei using Gaussian-type orbitals and periodic boundary conditions. This allows us to include relativistic effects variationally, which is important for compounds containing heavy elements and for a property dependent on the electronic structure close to the nuclei. The all-electron approach ensures an accurate treatment of both core and valence orbitals, as both are important in the evaluation of EFGs. Computational efficiency is achieved through the use of a recent implementation of density fitting in combination with quaternion algebra and restricted kinetic balance. We use the relativistic approach to calculate the EFGs in different arsenic, antimony, and bismuth halides and oxyhalides, and explore the importance of relativistic effects on EFGs in solids and compare these with results obtained for molecular species. Our calculations contribute to establishing a reliable estimate for the nuclear quadrupole moment of , for which our best estimate is mb, in excellent agreement both with molecular data and a recent reevaluation of the nuclear quadrupole moment obtained from atomic data and ab initio calculations. Our results suggest that there is a need to revisit the experimental data for the EFGs of several bismuth oxyhalides.
我们利用高斯型轨道和周期性边界条件，提出了原子核处电场梯度（EFGs）的全电子四分量相对论实现方法。这使我们能够将相对论效应变化纳入其中，这对于含有重元素的化合物和依赖于靠近原子核的电子结构的性质非常重要。全电子方法确保了对核轨道和价轨道的精确处理，因为这两种轨道在 EFG 评估中都很重要。通过使用最新实现的密度拟合，结合四元数代数和受限动力学平衡，实现了计算效率。我们使用相对论方法计算了不同砷、锑和铋卤化物和氧卤化物中的 EFGs，探讨了相对论效应对固体中 EFGs 的重要性，并将其与分子物种的计算结果进行了比较。我们的计算有助于为 Bi209 的核四极矩建立一个可靠的估计值，我们的最佳估计值为-428(17) mb，这与分子数据以及最近从原子数据和 ab initio 计算中获得的核四极矩的重新评估结果非常一致。我们的结果表明，有必要重新审视几种氧卤化铋的 EFG 的实验数据。
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Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.035153
Pei Sun, Yi Qiao, Tao Yang, Junpeng Cao, Wen-Li Yang
In this study, we explore the precise physical quantities in the thermodynamic limit of the one-dimensional Hubbard model with nonparallel boundary magnetic fields based on the off-diagonal Bethe ansatz solution. A particular emphasis is placed on the half-filling condition to investigate the distinct patterns of Bethe roots in the reduced Bethe ansatz equations for different boundary parameters. The ground state of the system can be divided into five regions according to the distribution of Bethe roots. By analyzing these patterns, we calculate the densities of states, ground-state energy density, and surface energy. The results reveal the existence of stable-boundary bound states, which are dependent on specific constraints regarding the boundary magnetic fields.
{"title":"Exact surface energy of the Hubbard model with nonparallel boundary magnetic fields","authors":"Pei Sun, Yi Qiao, Tao Yang, Junpeng Cao, Wen-Li Yang","doi":"10.1103/physrevb.110.035153","DOIUrl":"https://doi.org/10.1103/physrevb.110.035153","url":null,"abstract":"In this study, we explore the precise physical quantities in the thermodynamic limit of the one-dimensional Hubbard model with nonparallel boundary magnetic fields based on the off-diagonal Bethe ansatz solution. A particular emphasis is placed on the half-filling condition to investigate the distinct patterns of Bethe roots in the reduced Bethe ansatz equations for different boundary parameters. The ground state of the system can be divided into five regions according to the distribution of Bethe roots. By analyzing these patterns, we calculate the densities of states, ground-state energy density, and surface energy. The results reveal the existence of stable-boundary bound states, which are dependent on specific constraints regarding the boundary magnetic fields.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750274","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}
Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.l041405
Mo-Han Zhang, Fei Gao, Aleksander Bach Lorentzen, Ya-Ning Ren, Ruo-Han Zhang, Xiao-Feng Zhou, Rui Dong, Shi-Wu Gao, Mads Brandbyge, Lin He
It has long been an ultimate goal to introduce chemical doping at the atomic level to precisely tune properties of materials. Two-dimensional materials have a natural advantage due to their high surface to volume ratio, but achieving this goal experimentally remains a huge challenge. Here, we demonstrate the ability to introduce chemical doping in graphene with atomic-level precision by controlling chemical adsorption of individual Se atoms, which are extracted from the that is underneath, at the interface of the heterostructures. Our scanning tunneling microscopy (STM) measurements, combined with first-principles calculations, reveal that individual Se atoms can chemisorb on three possible positions in graphene, which generate distinct pseudospin-mediated atomic-scale vortices in graphene. Furthermore, the chemisorbed positions of individual Se atoms can be manipulated by the STM tip, which enables us to achieve atomic-scale control of quantum interference of the pseudospin-mediated vortices in graphene. This result offers the promise of controlling properties of materials with atomic-level precision through chemical doping.
长期以来，在原子层面引入化学掺杂以精确调节材料特性一直是我们的终极目标。二维材料具有高表面体积比的天然优势，但要在实验中实现这一目标仍是一个巨大的挑战。在这里，我们展示了通过控制石墨烯/WSe2 异质结构界面上单个 Se 原子的化学吸附，在石墨烯中引入原子级精度的化学掺杂的能力。我们的扫描隧道显微镜（STM）测量结果与第一原理计算相结合，揭示了单个硒原子可以在石墨烯的三个可能位置上发生化学吸附，从而在石墨烯中产生不同的伪ospin 介导的原子尺度漩涡。此外，单个硒原子的化学吸附位置可以通过 STM 针尖进行操纵，这使我们能够实现对石墨烯中伪斯宾介导的漩涡的原子尺度量子干涉控制。这一结果为通过化学掺杂以原子级精度控制材料特性带来了希望。
{"title":"Atomic-level precision creation and manipulation of interfacial Se chemisorbates in graphene/WSe2 heterostructures","authors":"Mo-Han Zhang, Fei Gao, Aleksander Bach Lorentzen, Ya-Ning Ren, Ruo-Han Zhang, Xiao-Feng Zhou, Rui Dong, Shi-Wu Gao, Mads Brandbyge, Lin He","doi":"10.1103/physrevb.110.l041405","DOIUrl":"https://doi.org/10.1103/physrevb.110.l041405","url":null,"abstract":"It has long been an ultimate goal to introduce chemical doping at the atomic level to precisely tune properties of materials. Two-dimensional materials have a natural advantage due to their high surface to volume ratio, but achieving this goal experimentally remains a huge challenge. Here, we demonstrate the ability to introduce chemical doping in graphene with atomic-level precision by controlling chemical adsorption of individual Se atoms, which are extracted from the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>WSe</mi><mn>2</mn></msub></math> that is underneath, at the interface of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mtext>graphene</mtext><mo>/</mo><msub><mi>WSe</mi><mn>2</mn></msub></math> heterostructures. Our scanning tunneling microscopy (STM) measurements, combined with first-principles calculations, reveal that individual Se atoms can chemisorb on three possible positions in graphene, which generate distinct pseudospin-mediated atomic-scale vortices in graphene. Furthermore, the chemisorbed positions of individual Se atoms can be manipulated by the STM tip, which enables us to achieve atomic-scale control of quantum interference of the pseudospin-mediated vortices in graphene. This result offers the promise of controlling properties of materials with atomic-level precision through chemical doping.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750279","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}
Pub Date : 2024-07-23DOI: 10.1103/physrevb.110.035424
Sonu Verma, Moon Jip Park
Bulk-boundary correspondence (BBC) of symmetry-protected topological (SPT) phases relates the nontrivial topological invariant of the bulk to the number of topologically protected boundary states. Recently, a finer classification of SPT phases in Hermitian systems has been discovered, known as subsymmetry-protected topological (sub-SPT) phases [Wang et al., Nat. Phys.19, 992 (2023)]. In sub-SPT phases, a fraction of the boundary states is protected by the subsymmetry of the system, even when the full symmetry is broken. While the conventional topological invariant derived from the Bloch band is not applicable to describe the BBC in these systems, we propose to use the non-Bloch topological band theory to describe the BBC of sub-SPT phases. Using the concept of the generalized Brillouin zone (GBZ), where Bloch momenta are generalized to take complex values, we show that the non-Bloch band theory naturally gives rise to a non-Bloch topological invariant, establishing the BBC in both SPT and sub-SPT phases. In a one-dimensional system, we define the winding number, whose physical meaning corresponds to the reflection amplitude in the scattering matrix. Furthermore, the non-Bloch topological invariant characterizes the hidden intrinsic topology of the GBZ under translation symmetry-breaking boundary conditions. The topological phase transitions are characterized by the generalized momenta touching the GBZ, which accompanies the emergence of diabolic or band-touching points. Additionally, we discuss the BBCs in the presence of local or global full-symmetry or subsymmetry-breaking deformations.
{"title":"Non-Bloch band theory of subsymmetry-protected topological phases","authors":"Sonu Verma, Moon Jip Park","doi":"10.1103/physrevb.110.035424","DOIUrl":"https://doi.org/10.1103/physrevb.110.035424","url":null,"abstract":"Bulk-boundary correspondence (BBC) of symmetry-protected topological (SPT) phases relates the nontrivial topological invariant of the bulk to the number of topologically protected boundary states. Recently, a finer classification of SPT phases in Hermitian systems has been discovered, known as subsymmetry-protected topological (sub-SPT) phases [Wang <i>et al.</i>, <span>Nat. Phys.</span> <b>19</b>, 992 (2023)]. In sub-SPT phases, a fraction of the boundary states is protected by the subsymmetry of the system, even when the full symmetry is broken. While the conventional topological invariant derived from the Bloch band is not applicable to describe the BBC in these systems, we propose to use the non-Bloch topological band theory to describe the BBC of sub-SPT phases. Using the concept of the generalized Brillouin zone (GBZ), where Bloch momenta are generalized to take complex values, we show that the non-Bloch band theory naturally gives rise to a non-Bloch topological invariant, establishing the BBC in both SPT and sub-SPT phases. In a one-dimensional system, we define the winding number, whose physical meaning corresponds to the reflection amplitude in the scattering matrix. Furthermore, the non-Bloch topological invariant characterizes the hidden intrinsic topology of the GBZ under translation symmetry-breaking boundary conditions. The topological phase transitions are characterized by the generalized momenta touching the GBZ, which accompanies the emergence of diabolic or band-touching points. Additionally, we discuss the BBCs in the presence of local or global full-symmetry or subsymmetry-breaking deformations.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750311","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}
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