Light Induced Quantum Anomalous Hall Effect in Cubic Rashba Spin-Orbit Coupled Systems

TL;DR

This paper explores how circularly polarized light induces topological phase transitions in a 2D electron system with cubic Rashba spin-orbit coupling, leading to quantized anomalous Hall effects and new topological phases.

Contribution

It demonstrates the light-induced topological phases in systems with cubic Rashba coupling and analyzes the effects of linear Rashba and Dresselhaus terms on these phases.

Findings

Light induces Chern insulating phases with C=0, 1, and 3.

Linear Rashba shifts Dirac points without changing topology.

Dresselhaus coupling enables topological transitions at small couplings.

Abstract

We investigate topological phase transitions in a two-dimensional electron system with cubic Rashba spin-orbit coupling driven by circularly polarized light. Within the Floquet framework, we demonstrate that light-matter interaction induces nontrivial band topology characterized by a quantized anomalous Hall response, with Chern insulating phases of C = 0, 1, and 3. These transitions are governed by gap closings at high-symmetry points in the Brillouin zone, controlled by the intensity and energy of the incident light. Introducing a weak linear Rashba term displaces Dirac points in momentum space without modifying the topology, whereas a purely linear Rashba system remains topologically trivial (C = 0). When both linear and cubic Rashba couplings are finite, the linear term confines nonzero-Chern phases to narrow parameter windows. In contrast, incorporating a linear Dresselhaus term into the cubic Rashba system can trigger topological transitions even at small coupling strengths. These results clarify the interplay between distinct spin-orbit interactions in Floquet-engineered Chern insulators and offer experimentally relevant pathways for achieving light-controlled topological phases.