Eur. Phys. J. B (2014) 87: 167
https://doi.org/10.1140/epjb/e2014-50223-1

Regular Article

Persistent current of relativistic electrons on a Dirac ring in presence of impurities

¹ S.N. Bose National Centre for Basic Sciences, Salt Lake, 700098 Kolkata, India
² Department of Physics, University of Basel Klingelbergstrasse 82, 4056 Basel, Switzerland

^a Present address: PSE Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
^b e-mail: arijit.saha@unibas.ch

Received: 1 April 2014
Received in final form: 14 May 2014
Published online: 1 August 2014

Abstract

We study the behaviour of persistent current of relativistic electrons on a one dimensional ring in presence of attractive/repulsive scattering potentials. In particular, we investigate the persistent current in accordance with the strength as well as the number of the scattering potential. We find that in presence of single scatterer the persistent current becomes smaller in magnitude than the scattering free scenario. This behaviour is similar to the non-relativistic case. Even for a very strong scattering potential, finite amount of persistent current remains for a relativistic ring. In presence of multiple scatterer we observe that the persistent current is maximum when the scatterers are placed uniformly compared to the current averaged over random configurations. However if we increase the number of scatterers, we find that the random averaged current increases with the number of scatterers. The latter behaviour is in contrast to the non-relativistic case.