Control of dimer chain topology by Rashba-Dresselhaus spin-orbit coupling

TL;DR

This paper demonstrates how Rashba-Dresselhaus spin-orbit coupling in a dimer chain can be used to control topological phases and emulate various quantum models, with potential applications in topological photonics and quantum simulation.

Contribution

It introduces a method to manipulate topological properties of a dimer chain via RDSOC, enabling simulation of different Hamiltonians and control of edge states.

Findings

RDSOC acts as a synthetic gauge field controlling tunneling sign and magnitude.

Switchable RDSOC allows tuning of band topology and edge states.

Implementation in liquid crystal microcavities enables experimental control.

Abstract

We study theoretically a dimer chain in the presence of Rashba-Dresselhaus spin-orbit coupling (RDSOC) with equal strength. We show that the RDSOC can be described as a synthetic gauge field that controls not only the magnitude but also the sign of tunneling coefficients between sites. This allows to emulate not only a Su-Schrieffer-Heeger chain which is commonly implemented in various platforms, but also, all energy spectra of the transverse field Ising model with both ferromagnetic and antiferromagnetic coupling. We simulate a realistic implementation of these effective Hamiltonians based on liquid crystal microcavities. In that case, the RDSOC can be switched on and off by an applied voltage, which controls the band topology, the existence and characteristics of topological edge states, or the nature of the ground state. This setting is promising for topological photonics applications and from a quantum simulation perspective.