Zak Phase Induced Topological Nonreciprocity

TL;DR

This paper demonstrates how the Zak phase in 1D SSH superradiance lattices induces optical nonreciprocity in room-temperature atoms, offering a compact and robust approach for nonreciprocal photonic devices.

Contribution

It introduces a novel mechanism linking 1D topological phases to optical nonreciprocity, avoiding complex fabrication and modulation requirements.

Findings

Different absorption spectra for opposite directions due to Zak phase

Optical nonreciprocity achieved in room-temperature atomic systems

Simplified design of topologically resilient nonreciprocal devices

Abstract

Topological physics provides novel insights for designing functional photonic devices, such as magnetic-free optical diodes, which are important in optical engineering and quantum information processing. Past efforts mostly focus on the topological edge modes in two-dimensional (2D) photonic Chern lattices, which, however, require delicate fabrication and temporal modulation. In particular, the 1D nonreciprocal edge mode needs to be embedded in a 2D lattice, contradicting with the compactness of integrated photonics. To address these challenges, we investigate the optical nonreciprocity of the 1D Su-Schrieffer-Heeger (SSH) superradiance lattices in room-temperature atoms. The probe fields propagating in two opposite directions perceive two different SSH topological phases, which have different absorption spectra due to the interplay between the Zak phase and the thermal motion of atoms, resulting in optical nonreciprocity. Our findings reveal the relationship between 1D topological matter and optical nonreciprocity, simplifying the design of topologically resilient nonreciprocal devices.