Silicene dynamic optical response in the presence of external electric and exchange fields

Date
2022-01-04
Advisor
Instructor
Source Title
Journal of Physics: Condensed Matter
Print ISSN
0953-8984
Electronic ISSN
1361-648X
Publisher
Institute of Physics Publishing Ltd.
Volume
34
Issue
11
Pages
1 - 11
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

We investigate the dynamic optical transition of monolayer silicene in the presence of external electric and exchange fields within the low-energy tight-binding model. Applying external electric and exchange fields breaks the silicene band structure spin and valley degeneracies. Three phases of silicene corresponding to different strengths of perpendicular electric field with respect to the spin–orbit coupling (Δz < Δso, Δz = Δso and Δz > Δso) are considered. We obtain the spin-valley-dependent optical responses to the incoming circularly polarized light using the Kubo formula. We show and discuss how the magnitude and direction of the transverse and longitudinal optical responses of such a system change with the electric and exchange fields. Our calculations suggest that the intraband part of the longitudinal optical response as well as the initial point of the interband part have strong dependencies on the exchange field. Furthermore, we show that one of the spin subbands plays a dominant role in the response to polarized light. Depending on the type of incident light polarization, the dominant subband may change. Our results shed light on the relation between silicene dynamic optical responses and externally applied fields.

Course
Other identifiers
Book Title
Keywords
Silicene, Optical response, Electric and exchange fields, Kubo formula, Circular polarization
Citation
Published Version (Please cite this version)