Three-dimensional Fractional Topological Insulators in Coupled Rashba Layers

We propose a model of three-dimensional topological insulators consisting of weakly coupled
electron- and hole-gas layers with Rashba spin-orbit interaction stacked along a given axis [1,2]. We show that in the presence of strong electron-electron interactions the system realizes a fractional strong topological insulator, where the rotational symmetry and condensation energy arguments still allow us to treat the problem as quasi-one-dimensional with bosonization techniques [1]. We also show that if Rashba and Dresselhaus spin-orbit interaction terms are equally strong, by doping the system with magnetic impurities, one can bring it into the Weyl semimetal phase [1].


[1] Y. Volpez, D. Loss, and J. Klinovaja, Phys. Rev. B 96, 085422 (2017).
[2] L. Trifunovic, D. Loss, and J. Klinovaja, Phys. Rev. B 93, 205406 (2016).