Structural and magnetic response of CrI3 monolayer to electric field

Abstract

A recent theoretical study reported large structural response to perpendicular electric fields in monolayer CrI3, which could be related to the microscopic origin of the technologically promising and experimentally observed electrical switching of magnetization in bilayer CrI3. However, these theoretical results are contrary to a previous theoretical finding of only slight changes under a strong electric field in CrI3. Here, we investigate the effects of perpendicular electric fields on the CrI3 monolayer using density-functional theory for various field strengths. Conclusively, we find an extremely small structural response to the electric field, due to a very efficient electronic screening of the field within the monolayer. Therefore, it cannot be the origin of the observed electrical switching of magnetization in the bilayer CrI3. Furthermore, we find the linear-response trends of the weak structural changes to persist up to a field value of 0.45 V/Å, in which range the Cr magnetic moment remains constant.