Nature of interacting electron states of Coulomb glass in local energy minima

Abstract

Non-equilibrium relaxation of Coulomb glass in disordered thin films is investigated by kinetic Monte Carlo simulation. We numerically confirm aging phenomena in the autocorrelation function C(t, t_W ) in a quasi-two-dimensional system with finite thickness and clarify the effect of an external electric field on the elongated relaxation time due to aging. We also study the statistical properties of electron states belonging to local energy minima in random site models. Our results highlight the difference in the properties of energy landscape between two different models to describe Coulomb glass, called the random site model and the lattice model.

Keywords:

• kinetic Monte Carlo methods
• relaxation
• electron correlations
• simulated annealing
• aging

Acknowledgements

The authors thank the Supercomputer Centre, Institute of Solid State Physics at the University of Tokyo for the use of their facilities. This work was supported in part by a Grant-in-Aid from the Japan Ministry of Education, Science, Sports, and Culture for Scientific Research.