Orbital doublet driven even-spin Chern insulators

Liu, Lu1,2,3; Liu, Yuntian1,2; Li, Jiayu1,2; Wu, Hua3,4,5; Liu, Qihang1,2,6

2024-07-31

10.1103/PhysRevB.110.035161

PHYSICAL REVIEW B   影响因子和分区

2469-9950

2469-9969

Quantum spin Hall insulators hosting edge spin currents hold great potential for low-power spintronic devices. In this paper, we present a universal approach to achieve a high and near-quantized spin Hall conductance plateau within a sizable bulk gap. Using a nonmagnetic four-band model Hamiltonian, we demonstrate that an even-spin Chern (ESC) insulator can be accessed by tuning the sign of spin-orbit coupling (SOC) within a crystal symmetry-enforced orbital doublet. With the assistance of a high-spin Chern number of CS = -2 and spin U (1) quasisymmetry, this orbital doublet driven ESC phase is endowed with the near double quantized spin Hall conductance. We identify 12 crystallographic point groups supporting such a sign-tunable SOC. Furthermore, we apply our theory to realistic examples, and show the phase transition from a trivial insulator governed by positive SOC in the RuI3 monolayer to an ESC insulator dominated by negative SOC in the RuBr3 monolayer. This orbital doublet driven ESC insulator, RuBr3, showcases nontrivial characteristics including helical edge states, near double quantized spin Hall conductance, and robust corner states. Our work provides different pathways in the pursuit of the long-sought quantum spin Hall insulators.

SCI ; EI

英语

第一 ; 通讯

National Key R&D Program of China[2020YFA0308900] ; National Natural Science Foundation of China["12274194","12174062","12241402"] ; Guangdong Provincial Key Laboratory for Computational Science and Material Design[2019B030301001] ; Shenzhen Science and Technology Program[RCJC20221008092722009] ; Sci-ence, Technology and Innovation Commission of Shenzhen Municipality[ZDSYS20190902092905285]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:001284717000002

AMER PHYSICAL SOC

PHYSICS

Web of Science

1.Southern Univ Sci & Technol, Dept Phys, Shenzhen 518055, Peoples R China
2.Southern Univ Sci & Technol, Shenzhen Inst Quantum Sci & Engn SIQSE, Shenzhen, Peoples R China
3.Sudan Univ, Dept Phys, Lab Computat Phys Sci MOE, State Key Lab Surface Phys, Shanghai 200433, Peoples R China
4.Shanghai Qi Zhi Inst, Shanghai 200232, Peoples R China
5.Collaborat Innovat Ctr Adv Microstruct, Nanjing 210093, Peoples R China
6.Southern Univ Sci & Technol, Guangdong Prov Key Lab Computat Sci & Mat Design, Shenzhen 518055, Peoples R China

Liu, Lu,Liu, Yuntian,Li, Jiayu,et al. Orbital doublet driven even-spin Chern insulators[J]. PHYSICAL REVIEW B,2024,110(3).

Liu, Lu,Liu, Yuntian,Li, Jiayu,Wu, Hua,&Liu, Qihang.(2024).Orbital doublet driven even-spin Chern insulators.PHYSICAL REVIEW B,110(3).

Liu, Lu,et al."Orbital doublet driven even-spin Chern insulators".PHYSICAL REVIEW B 110.3(2024).