Zero-energy states bound to a magnetic pi-flux vortex in a two-dimensional topological insulator

Abstract

We show that the existence of a pair of zero-energy modes bound to a vortex carrying a pi-flux is a generic feature of the topologically non-trivial phase of the M-B model, which was introduced to describe the topological band insulator in HgTe quantum wells. We explicitly find the form of the zero-energy states of the corresponding Dirac equation, which contains a novel momentum-dependent mass term and describes a generic topological transition in a band insulator. The obtained modes are exponentially localized in the vortex-core, with the dependence of characteristic length on the parameters of the model matching the dependence extracted from a lattice version of the model. We consider in full generality the short-distance regularization of the vector potential of the vortex, and show that a particular choice yields the modes localized and simultaneously regular at the origin. Finally, we also discuss a realization of two-dimensional spin-charge separation through the vortex zero-modes.

30 pages, 2 figures; accepted for publication by Nuclear Physics B

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Cited by in corpus (5)

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• Dipolar Weyl semimetals
• Three-dimensional $\mathbb{Z}$ topological insulators without reflection symmetry
• Projected branes as platforms for crystalline, superconducting, and higher-order topological phases
• Critical States of Fermions with ${\mathbb{Z}}_2$ Flux Disorder