A recently discovered family of kagome lattice materials,AV_(3)Sb_(5)(A=K,Rb,Cs),has attracted great interest,especiallyin the debate over their dominant superconducting pairing symmetry.To explore this issue,we study...A recently discovered family of kagome lattice materials,AV_(3)Sb_(5)(A=K,Rb,Cs),has attracted great interest,especiallyin the debate over their dominant superconducting pairing symmetry.To explore this issue,we study the superconductingpairing behavior within the kagome-lattice Hubbard model through the constrained path Monte Carlo method.It isfound that doping around the Dirac point generates a dominant next-nearest-neighbor-d pairing symmetry driven by on-siteCoulomb interaction U.However,when considering the nearest-neighbor interaction V,it may induce nearest-neighbor-ppairing to become the preferred pairing symmetry.Our results provide useful information to identify the dominant superconductingpairing symmetry in the AV_(3)Sb_(5)family.展开更多
We design two new layered indium halide compounds LaOInF_(2)and LaOInCl_(2)by means of first-principles calculations and evolutionary crystal structure prediction.We find both compounds crystallize in a tetragonal str...We design two new layered indium halide compounds LaOInF_(2)and LaOInCl_(2)by means of first-principles calculations and evolutionary crystal structure prediction.We find both compounds crystallize in a tetragonal structure with P4/nmm space group and have indirect band gaps of 2.58 eV and 3.21 eV,respectively.By substituting O with F,both of them become metallic and superconducting at low temperature.The F-doping leads to strong electron-phonon coupling in the low-energy acoustic phonon modes which is mainly responsible for the induced superconductivity.The total electron-phonon coupling strength are 1.86 and 1.48,while the superconducting transition temperature(T_(c))are about 7.2 K and 6.5 K with 10%and 5%F doping for LaOInF_(2)and LaOInCl_(2),respectively.展开更多
SrIrO_(3),a Dirac material with a strong spin-orbit coupling(SOC),is a platform for studying topological properties in strongly correlated systems,where its band structure can be modulated by multiple factors,such as ...SrIrO_(3),a Dirac material with a strong spin-orbit coupling(SOC),is a platform for studying topological properties in strongly correlated systems,where its band structure can be modulated by multiple factors,such as crystal symmetry,elements doping,oxygen vacancies,magnetic field,and temperature.Here,we find that the engineered carrier density plays a critical role on the magnetoelectric transport properties of the topological semimetal SrIrO_(3).The decrease of carrier density subdues the weak localization and the associated negative magnetoresistance,while enhancing the SOC-induced weak anti-localization.Notably,the sample with the lowest carrier density exhibits high-field positive magnetoresistance,suggesting the presence of a Dirac cone.In addition,the anisotropic magnetoresistance indicates the anisotropy of the electronic structure near the Fermi level.The engineering of carrier density provides a general strategy to control the Fermi surface and electronic structure in topological materials.展开更多
基金supported by Beijing Natural Science Foundation(Grant No.1242022).The numerical simulations in this work were performed at HSCC of Beijing Normal University.
文摘A recently discovered family of kagome lattice materials,AV_(3)Sb_(5)(A=K,Rb,Cs),has attracted great interest,especiallyin the debate over their dominant superconducting pairing symmetry.To explore this issue,we study the superconductingpairing behavior within the kagome-lattice Hubbard model through the constrained path Monte Carlo method.It isfound that doping around the Dirac point generates a dominant next-nearest-neighbor-d pairing symmetry driven by on-siteCoulomb interaction U.However,when considering the nearest-neighbor interaction V,it may induce nearest-neighbor-ppairing to become the preferred pairing symmetry.Our results provide useful information to identify the dominant superconductingpairing symmetry in the AV_(3)Sb_(5)family.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2243300003)the National Natural Science Foundation of China(Grant No.12074041)the Fundamental Research Program of Shanxi Province,China(Grant No.202203021222228).The calculations were carried out with high performance computing cluster of Beijing Normal University in Zhuhai.
文摘We design two new layered indium halide compounds LaOInF_(2)and LaOInCl_(2)by means of first-principles calculations and evolutionary crystal structure prediction.We find both compounds crystallize in a tetragonal structure with P4/nmm space group and have indirect band gaps of 2.58 eV and 3.21 eV,respectively.By substituting O with F,both of them become metallic and superconducting at low temperature.The F-doping leads to strong electron-phonon coupling in the low-energy acoustic phonon modes which is mainly responsible for the induced superconductivity.The total electron-phonon coupling strength are 1.86 and 1.48,while the superconducting transition temperature(T_(c))are about 7.2 K and 6.5 K with 10%and 5%F doping for LaOInF_(2)and LaOInCl_(2),respectively.
基金supported by the National Natural Science Foundation of China(Grant Nos.T2350005 and 5227123)the National Science Fund for Distinguished Young Scholars(Grant No.52225205)+1 种基金the National Key Research and Development Program of China(Grant Nos.2021YFA0718700 and 2023YFA1406500)the Fundamental Research Funds for the Central Universities。
文摘SrIrO_(3),a Dirac material with a strong spin-orbit coupling(SOC),is a platform for studying topological properties in strongly correlated systems,where its band structure can be modulated by multiple factors,such as crystal symmetry,elements doping,oxygen vacancies,magnetic field,and temperature.Here,we find that the engineered carrier density plays a critical role on the magnetoelectric transport properties of the topological semimetal SrIrO_(3).The decrease of carrier density subdues the weak localization and the associated negative magnetoresistance,while enhancing the SOC-induced weak anti-localization.Notably,the sample with the lowest carrier density exhibits high-field positive magnetoresistance,suggesting the presence of a Dirac cone.In addition,the anisotropic magnetoresistance indicates the anisotropy of the electronic structure near the Fermi level.The engineering of carrier density provides a general strategy to control the Fermi surface and electronic structure in topological materials.
