Switching Rashba spin-splitting by reversing electric-field direction

The manipulation of the Rashba spin-splitting is crucial for the development of nanospintronic technology. Here, it is proposed that the Rashba spin-splitting can be turned on and off by reversing electric-field direction. By the first-principle calculations, our proposal is illustrated by a concret...

Full description

Saved in:
Bibliographic Details
Published inarXiv.org
Main Authors San-Dong, Guo, Jing-Xin, Zhu, Hao-Tian, Guo, Wang, Bing, Guang-Zhao, Wang, Yee-Sin Ang
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 29.09.2022
Subjects
Dynamic stability
Electric fields
Electronegativity
First principles
Monolayers
Piezoelectricity
Splitting
Switching
Two dimensional materials
Online AccessGet full text

Cover

More Information
Summary:The manipulation of the Rashba spin-splitting is crucial for the development of nanospintronic technology. Here, it is proposed that the Rashba spin-splitting can be turned on and off by reversing electric-field direction. By the first-principle calculations, our proposal is illustrated by a concrete example of Janus monolayer RbKNaBi. The designed RbKNaBi possesses dynamical, thermal and mechanical stability, and is a large-gap quantum spin Hall insulator (QSHI) with Rashba spin-splitting near the Fermi level. A small built-in electric field is predicted due to very small electronegativity difference between the bottom and top atoms, which is very key to switch Rashba spin-splitting through the experimentally available electric field intensity. Due to out-of-plane structural asymmetry, the Janus monolayer has distinctive behaviors by applying external electric field \(E\) with the same magnitude but different directions (\(z\) or \(-z\)). Our results reveal that the Rashba energy (\(E_R\)) and Rashba constant (\(\alpha_R\)) are increased by the positive \(E\), while a negative \(E\) suppresses the Rashba splitting to disappear, and then appears again. In a certain \(E\) region (0.15 \(\mathrm{V/\AA}\) to 0.25 \(\mathrm{V/\AA}\)), switching Rashba spin-splitting can be achieved by only reversing electric-field direction. Besides, the piezoelectric strain coefficients \(d_{11}\) and \(d_{31}\) (5.52 pm/V and -0.41 pm/V) are predicted, which are higher than or compared with those of many 2D materials. By piezoelectric effect, the strain can also be used to tune Rashba spin-splitting of RbKNaBi. Moreover, a possible spintronic device is proposed to realize the function of spintronic switch.
ISSN:2331-8422