Kagome bands and magnetism in MoTe2-x kagome monolayers

Kagome bands and magnetism in MoTe2-x kagome monolayers

Jiaqi Dai, Zhongqin Zhang, Zemin Pan, Cong Wang, Chendong Zhang*, Zhihai Cheng,  and Wei Ji*

Kagome lattices facilitate various quantum phases, yet in bulk materials, their kagome flat-bands often interact with bulk bands, suppressing kagome electronic characteristics for hosting these phases. Here, we use density-functional-theory calculations to predict the geometric and electronic structures, as well as the topological and magnetic properties, of a series of MoTe2-x kagome monolayers formed by mirror-twin-boundary (MTB) loops. We analyze nine MTB-loop configurations of varying sizes and arrangements to assess their impact on various properties. Within the intrinsic bandgap of MoTe2, we identify two sets of kagome bands, originating from in-plane and out-of-plane Te p-orbitals at MTB-loop edges and -vertices, respectively. Three configurations exhibit superior stability, while three others show comparable stability. Among these, four display bandgaps and potentially non-zero Z2 topological invariants, suggesting possible topological phases, while the remaining two are metallic and feature Stoner magnetization. These findings guide the design of kagome-based two-dimensional materials with tunable electronic, topological, and magnetic properties.

Nonvolatile Electric Control of Rashba Spin Splitting in Sb/In2Se3 Heterostructure

Nonvolatile Electric Control of Rashba Spin Splitting in Sb/In2Se3 Heterostructure

Haixia Cheng, Xu Sun, Jun Zhou*, Shijie Wang, Hang Su*, and Wei Ji*

Ferroelectric Rashba semiconductors (FRS) are highly demanded for their potential capability for nonvolatile electric control of electron spins. An ideal FRS is characterized by a combination of room temperature ferroelectricity and a strong Rashba effect, which has, however, been rarely reported. Herein, we designed a room-temperature FRS by vertically stacking a Sb monolayer on a room-temperature ferroelectric In2Se3 monolayer. Our first-principles calculations reveal that the Sb/In2Se3 heterostructure exhibits a clean Rashba splitting band near the Fermi level and a strong Rashba effect coupled to the ferroelectric order. Switching the electric polarization direction enhances the Rashba effect, and the flipping is feasible with a low energy barrier of 22 meV. This Rashba–ferroelectricity coupling effect is robust against changes of the heterostructure interfacial distance and external electric fields. Such a nonvolatile electrically tunable Rashba effect at room temperature enables potential applications in next-generation data storage and logic devices operated under small electrical currents.

杨紫尧 硕士生 Yang, Ziyao (M1 Student)

杨紫尧 硕士生 Yang, Ziyao (M1 Student)

基本信息
杨紫尧:2024级 硕士生
办公地点:北园物理楼206
电子邮箱:yangziyao@ruc.edu.cn
电  话:+86-10-62517997
传  真:+86-10-62517887
邮  编:100872

教育经历

(1) 2024-09 至今,中国人民大学,物理学系,硕士研究生,在读
(2) 2020-09至2024-06,东北师范大学,物理系,本科,理学学士

研究方向



代表性论文

冯佳佳 博士生 Feng, Jiajia (P1 Student)

冯佳佳 博士生 Feng, Jiajia (P1 Student)

基本信息
冯佳佳:2024级 直博生
办公地点:北园物理楼206
电子邮箱:fengjiajia355@ruc.edu.cn
电  话:+86-10-62517997
传  真:+86-10-62517887
邮  编:100872

教育经历

(1) 2024-09 至今,中国人民大学,物理学系,直博,在读
(2) 2020-09 至 2024-06,山东师范大学,物理系,本科,理学学士

研究方向

层间耦合材料的第一性原理计算,氧化物材料的第一性原理计算。

代表性论文

李文考 博士生 Li, Wenkao (P1 Student)

李文考 博士生 Li, Wenkao (P1 Student)

基本信息
李文考:2024级 直博生
办公地点:北园物理楼206
电子邮箱:liwenkao@ruc.edu.cn
电  话:+86-10-62517997
传  真:+86-10-62517887
邮  编:100872

教育经历

(1) 2024-09 至今,中国人民大学,物理学系,直博,在读
(2) 2020-09 至 2024-06,山东师范大学,物理系,本科,理学学士

研究方向

低维磁性材料的第一性原理计算,预测低维材料物性。

代表性论文