Nonlinear sigma-model approach to the coupled spin-charge dynamics in the presence of Rashba spin-orbit coupling (Conference Presentation)

Roberto Raimondi; Alessandro Veneri

doi:10.1117/12.2527690

10 September 2019 Nonlinear sigma-model approach to the coupled spin-charge dynamics in the presence of Rashba spin-orbit coupling (Conference Presentation)

Roberto Raimondi, Alessandro Veneri

Author Affiliations +

Proceedings Volume 11090, Spintronics XII; 110901W (2019) https://doi.org/10.1117/12.2527690
Event: SPIE Nanoscience + Engineering, 2019, San Diego, California, United States

Abstract

Spin-charge coupled dynamics is the subject of fundamental and applied research for its relevance in spintronics. In this context the understanding of the interplay between disorder and spin-orbit coupling (SOC) plays a key role. The nonlinear sigma model for disordered electron systems is a powerful effective field theory for transport phenomena in diffusive conductors and superconductors. At the tree level the nonlinear sigma model is equivalent to the Eilenberger and Usadel equations for the quasiclassical Keldysh Green function. The latter, which were originally developed for superconductors, have been extended in order to include SOC. Here we derive the nonlinear sigma model with Rashba SOC for the disordered two-dimensional electron gas (2DEG). By starting from a functional integral representation of the partition function for disordered fermions in the presence of Rashba SOC, we introduce the Q matrix (in Keldysh and spin space) field to decouple the effective fermion-fermion interaction introduced by the disorder average. After integrating out the fermion degrees of freedom, we get the effective action for the Q field. The saddle-point approximation reproduces the self-consistent Born approximation, in the presence of Rashba SOC. By restricting to the manifold QQ=1, we derive the nonlinear sigma model for diffusive spin and charge density modes. The Rashba SOC appears as a SU(2) gauge field coupled to the Q field. Nonuniform and time-dependent saddle-point solutions for the Q field obey the Usadel equation in the presence of Rashba SOC. Finally, extensions of the theory beyond the 2DEG are briefly discussed.

Conference Presentation

Citation Download Citation

Roberto Raimondi and Alessandro Veneri "Nonlinear sigma-model approach to the coupled spin-charge dynamics in the presence of Rashba spin-orbit coupling (Conference Presentation)", Proc. SPIE 11090, Spintronics XII, 110901W (10 September 2019); https://doi.org/10.1117/12.2527690

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
PRESENTATION

WATCH
PRESENTATION SAVE TO MY LIBRARY

GET CITATION

KEYWORDS

System on a chip

Fermions

Superconductors

Systems modeling

Applied research

Complex systems

Electron transport

Show All Keywords

Keywords/Phrases

Search In:

Publication Years