Topological phases and fractional excitations of the exciton condensate in a special class of bilayer systems

TL;DR

This paper explores how Rashba spin-orbit interaction in electron-hole bilayer systems with ferromagnetic films induces topological phases and fractional excitations in the exciton condensate at zero temperature.

Contribution

It demonstrates the emergence of topologically nontrivial phases and fractional excitations due to spin-orbit coupling and magnetization effects in a specific bilayer system.

Findings

Rashba spin-orbit interaction induces p  ip or p pairing states.

Topologically nontrivial phases host fractional quantum numbers.

Vortices exhibit Abelian statistics.

Abstract

We study the exciton condensate in zero temperature limit in a special class of electron-hole bilayer systems adjacent to insulating ferromagnetic films. With the self-consistent mean-field approximation, we find that the Rashba spin-orbit interaction in the electron and hole layers can induce the p \pm ip or p pairing states depending on the different magnetization of the overlapped ferromagnetic films. Correspondingly, the topologically nontrivial or trivial phases emerge. Furthermore, in the topologically nontrivial phase, the quasiparticle excitations of the U(1) vortex are attached to fractional quantum numbers and obey Abelian statistics.