The quantum anomalous Hall effect(QAHE) has special quantum properties that are ideal for possible future spintronic devices. However, the experimental realization is rather challenging due to its low Curie temperatur...The quantum anomalous Hall effect(QAHE) has special quantum properties that are ideal for possible future spintronic devices. However, the experimental realization is rather challenging due to its low Curie temperature and small non-trivial bandgap in two-dimensional(2D) materials. In this paper, we demonstrate through first-principles calculations that monolayer Co2Te material is a promising 2D candidate to realize QAHE in practice. Excitingly, through Monte Carlo simulations, it is found that the Curie temperature of single-layer Co2Te can reach 573 K. The band crossing at the Fermi level in monolayer Co2Te is opened when spin–orbit coupling is considered, which leads to QAHE with a sizable bandgap of Eg= 96 me V, characterized by the non-zero Chern number(C = 1) and a chiral edge state. Therefore, our findings not only enrich the study of quantum anomalous Hall effect, but also broaden the horizons of the spintronics and topological nanoelectronics applications.展开更多
Manipulation of the valley degree of freedom provides a new path for quantum information technology,but the real intrinsic large valley-polarization materials are rarely reported up to date.Here,we perform first-princ...Manipulation of the valley degree of freedom provides a new path for quantum information technology,but the real intrinsic large valley-polarization materials are rarely reported up to date.Here,we perform first-principles calculations to predict a class of 2H-phase single layer(SL)materials LuX_(2)(X=Cl,Br,I)to be ideal candidates.SL-Lu X_(2)are ferrovalley materials with a giant valley-polarization of 55 meV–148 meV as a result of its large spin–orbital coupling(SOC)and intrinsic ferromagnetism(FM).The magnetic transition temperatures of SL-LuI_(2)and SL-LuCl2are estimated to be 89 K–124 K,with a sizable magnetic anisotropy at out-of-plane direction.Remarkably,the anomalous valley Hall effect(AVHE)can be controlled in SL-LuX_(2)when an external electric field is applied.Moreover,the intrinsic valleypolarization of SL-LuI_(2)is highly robust for biaxial strain.These findings provide a promising ferrovalley material system for the experimentation of valleytronics and subsequent applications.展开更多
基金supported by the Taishan Scholar Program of Shandong Province, China (Grant No. ts20190939)the Independent Cultivation Program of Innovation Team of Jinan City (Grant No. 2021GXRC043)the National Natural Science Foundation of China (Grant No. 52173238)。
文摘The quantum anomalous Hall effect(QAHE) has special quantum properties that are ideal for possible future spintronic devices. However, the experimental realization is rather challenging due to its low Curie temperature and small non-trivial bandgap in two-dimensional(2D) materials. In this paper, we demonstrate through first-principles calculations that monolayer Co2Te material is a promising 2D candidate to realize QAHE in practice. Excitingly, through Monte Carlo simulations, it is found that the Curie temperature of single-layer Co2Te can reach 573 K. The band crossing at the Fermi level in monolayer Co2Te is opened when spin–orbit coupling is considered, which leads to QAHE with a sizable bandgap of Eg= 96 me V, characterized by the non-zero Chern number(C = 1) and a chiral edge state. Therefore, our findings not only enrich the study of quantum anomalous Hall effect, but also broaden the horizons of the spintronics and topological nanoelectronics applications.
基金the Taishan Scholar Program of Shandong Province,China(Grant No.ts20190939)the Independent Cultivation Program of Innovation Team of Jinan City(Grant No.2021GXRC043)the National Natural Science Foundation of China(Grant No.52173283).
文摘Manipulation of the valley degree of freedom provides a new path for quantum information technology,but the real intrinsic large valley-polarization materials are rarely reported up to date.Here,we perform first-principles calculations to predict a class of 2H-phase single layer(SL)materials LuX_(2)(X=Cl,Br,I)to be ideal candidates.SL-Lu X_(2)are ferrovalley materials with a giant valley-polarization of 55 meV–148 meV as a result of its large spin–orbital coupling(SOC)and intrinsic ferromagnetism(FM).The magnetic transition temperatures of SL-LuI_(2)and SL-LuCl2are estimated to be 89 K–124 K,with a sizable magnetic anisotropy at out-of-plane direction.Remarkably,the anomalous valley Hall effect(AVHE)can be controlled in SL-LuX_(2)when an external electric field is applied.Moreover,the intrinsic valleypolarization of SL-LuI_(2)is highly robust for biaxial strain.These findings provide a promising ferrovalley material system for the experimentation of valleytronics and subsequent applications.
