Topological polarization in graphene-like systems

de Nittis G, Lein M (2013)


Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2013

Journal

Publisher: Institute of Physics: Hybrid Open Access

Book Volume: 46

Article Number: 385001

Journal Issue: 38

DOI: 10.1088/1751-8113/46/38/385001

Abstract

In this paper we investigate the possibility of generating piezoelectric orbital polarization in graphene-like systems which are deformed periodically. We start with discrete two-band models which depend on control parameters; in this setting, time-dependent model Hamiltonians are described by loops in parameter space. Then, the gap structure at a given Fermi energy generates a non-trivial topology on parameter space which then leads to possibly non-trivial polarizations. More precisely, we show the polarization, as given by the King-Smith-Vanderbilt formula, depends only on the homotopy class of the loop; hence, a necessary condition for non-trivial piezo effects is that the fundamental group of the gapped parameter space must not be trivial. The use of the framework of non-commutative geometry implies that our results extend to systems with weak disorder. We then apply this analysis to the uniaxial strain model for graphene which includes nearest-neighbor hopping and a stagger potential, and show that it supports non-trivial piezo effects; this is in agreement with recent physics literature. © 2013 IOP Publishing Ltd.

Authors with CRIS profile

Involved external institutions

How to cite

APA:

de Nittis, G., & Lein, M. (2013). Topological polarization in graphene-like systems. Journal of Physics A: Mathematical and Theoretical, 46(38). https://doi.org/10.1088/1751-8113/46/38/385001

MLA:

de Nittis, Giuseppe, and Max Lein. "Topological polarization in graphene-like systems." Journal of Physics A: Mathematical and Theoretical 46.38 (2013).

BibTeX: Download