The effect of the geometric phase on spin-polarized
electron tunnelling
Zheng-Chuan Wang1, Gang Su1, Ling Li2 and Jie Gao2
1 Department of Physics, The Graduate School of the Chinese Academy of Sciences,
PO Box 3908, Beijing 100039, People’s Republic of China 2 Department of Physics, Sichuan University, Chengdu 610018, People’s Republic of China
Received 15 April 2004, in final form 20 July 2004
Published 3 September 2004
Online at stacks.iop.org/JPhysCM/16/6713
doi:10.1088/0953-8984/16/37/007

Abstract
In order to explore the effect of the geometric phase on the spin-polarized electron tunnelling in a ferromagnet/insulator/ferromagnet (FM/I/FM) junction, in this paper, we apply a voltage drop in the insulating layer and allow it to vary adiabatically with time t. Then the wavefunction will acquire a geometric phase which will give rise to an observable effect on the physical quantities of interest. The numerical results indicate that the geometric phase certainly has an influence on the differential conductance and the tunnelling magnetoresistance (TMR) in the spin-polarized tunnelling. We also show results for the conductance and TMR obtained by changing the orientation angle and the magnitude of the molecular field in the ferromagnets. An experimental profile for observing the effect of the geometric phase on the spin-polarized electron transport in a FM/I/FM tunnel junction is suggested.