Bias-dependent D'yakonov-Perel' spin relaxation in bilayer graphene

TL;DR

This paper investigates how the D'yakonov-Perel' spin relaxation mechanism affects electron spin relaxation times in bilayer graphene, revealing non-monotonic behavior influenced by bandstructure warping and external bias.

Contribution

It provides analytical and numerical analysis of spin relaxation in bilayer graphene considering trigonal warping effects, aligning with experimental data and suggesting spintronic device applications.

Findings

Spin relaxation time shows non-monotonic dependence on Fermi energy and bias.

Results match recent experimental measurements.

Potential for electrically controlled spin devices.

Abstract

We calculate the spin relaxation time of mobile electrons due to spin precession between random impurity scattering (D'yakonov-Perel' mechanism) in electrically gated bilayer graphene analytically and numerically. Due to the trigonal warping of the bandstructure, the spin relaxation time exhibits an interesting non-monotonic behavior as a function of both the Fermi energy and the interlayer bias potential. Our results are in good agreement with recent four-probe measurements of the spin relaxation time in bilayer graphene and indicate the possibility of an electrically-switched spin device.