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arXiv · 1407.2633

Effective field theory for the bulk-edge correspondence in a two-dimensional Z_2 topological insulator with Rashba interactions

Pedro R. S. Gomes·Po-Hao Huang·Claudio Chamon·Christopher Mudry
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Abstract

We determine the effective field theory in (2+1)-dimensional space and time that captures the long wave length and low-energy limit of fermions hopping on a honeycomb lattice at half-filling when both a dominant intrinsic and subdominant Rashba spin-orbit couplings are present. This effective field theory for a Z_2 topological insulator (the Kane-Mele model at vanishing uniform and staggered chemical potentials) is a perturbation around a double Chern-Simons theory, with the U(1) gauge invariance associated to spin conservation explicitly broken due to the Rashba spin orbit coupling. Nonetheless, we find that the effective field theory has a BRST symmetry that allows us to construct the bulk-edge correspondence.

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Pedro R. S. Gomes, Po-Hao Huang, Claudio Chamon, Christopher Mudry. 2014-07-09. Effective field theory for the bulk-edge correspondence in a two-dimensional Z_2 topological insulator with Rashba interactions. https://doi.org/10.1103/physrevb.90.115144

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