Peculiarities of dynamics of Dirac fermions associated with zero-mass lines
Abstract
Zero-mass lines result in appearance of linear dispersion modes for Dirac fermions. These modes play an important role in various physical systems. However, a Dirac fermion may not precisely follow a single zero-mass line, due to either tunneling between different lines or centrifugal forces. Being shifted from a zero-mass line the Dirac fermion acquires mass which can substantially influence its expected "massless" behavior. In the paper we calculate the energy gap caused by the tunneling between two zero-mass lines and show that its opening leads to the delocalization of linear dispersion modes. The adiabatic bending of a zero-mass line gives rise to geometric phases. These are the Berry phase, locally associated with a curvature, and a new phase resulting from the mass square asymmetry in the vicinity of a zero-mass line.
Keywords
Cite
@article{arxiv.1206.2244,
title = {Peculiarities of dynamics of Dirac fermions associated with zero-mass lines},
author = {Timur Tudorovskiy and Mikhail I. Katsnelson},
journal= {arXiv preprint arXiv:1206.2244},
year = {2013}
}
Comments
6 pages, 4 figures. In the second version some references were added and minor changes were made in the introduction