Anomalous Topological Bloch Oscillations under Non-Abelian Gauge Fields

TL;DR

This paper demonstrates how non-Abelian gauge fields engineered via spin-orbit coupling induce anomalous, asymmetric topological Bloch oscillations in quantum systems, revealing new control mechanisms for topological quantum dynamics.

Contribution

It introduces a method to generate non-Abelian gauge fields through SOC in a honeycomb lattice, leading to novel anomalous Bloch oscillations with tunable asymmetric features.

Findings

Discovery of asymmetric topological Bloch oscillations (ATBOs)

Tunable freezing effect in oscillation cycles

SOC parameters control the oscillation dynamics

Abstract

Topological Bloch oscillations are a hallmark of quantum transport phenomenon in which wavepackets undergo oscillatory motion driven by the interplay between an external force and topological edge states and serve as a powerful dynamical probe for the geometric properties of topological bands. Spin-orbit coupling (SOC) has also emerged as a crucial ingredient for manipulating quantum states in materials, with the corresponding gauge fields arising from the Rashba and Dresselhaus interactions. In this work, we investigate the propagation of spinor wavepackets in a honeycomb Zeeman lattice governed by the Gross-Pitaevskii equation. By tuning the relative strengths of Rashba and Dresselhaus SOC, we engineer a non-Abelian gauge field that drives anomalous topological Bloch oscillations (ATBOs). Unlike conventional topological Bloch oscillation (TBOs), these ATBOs exhibit asymmetric motion, including a freezing effect in one half of the oscillation cycle, which can be tuned by the SOC parameters and external forces. Our findings establish SOC-based non-Abelian gauge fields as a powerful mechanism controlling topological quantum dynamics, with implications for spintronic devices and quantum data processing.