Topologically Protected Quantum Coherence in a Superatom
Abstract
Exploring the properties and applications of topological quantum states is essential to better understand topological matter. Here, we theoretically study a quasi-one-dimensional topological atom array. In the low-energy regime, the atom array is equivalent to a topological superatom. Driving the superatom in a cavity, we study the interaction between light and topological quantum states. We find that the edge states exhibit topology-protected quantum coherence, which can be characterized from the photon transmission. This quantum coherence helps us to find a superradiance-subradiance transition, and we also study its finite-size scaling behavior. The superradiance-subradiance transition also exists in symmetry-breaking systems. More importantly, it is shown that the quantum coherence of the subradiant edge state is robust to random noises, allowing the superatom to work as a topologically protected quantum memory. We suggest a relevant experiment with three-dimensional circuit QED. Our study may have applications in quantum computation and quantum optics based on topological edge states.
Cite
@article{arxiv.1902.10883,
title = {Topologically Protected Quantum Coherence in a Superatom},
author = {Wei Nie and Z. H. Peng and Franco Nori and Yu-xi Liu},
journal= {arXiv preprint arXiv:1902.10883},
year = {2020}
}