Realizing Topological Transition in a Non-Hermitian Quantum Walk with Circuit QED

TL;DR

This paper demonstrates that topological transitions in a non-Hermitian quantum walk are robust against dephasing effects and discusses experimental realization in circuit QED systems.

Contribution

It extends the non-Hermitian quantum walk model to include dephasing and shows topological transition robustness, proposing experimental implementation in circuit QED.

Findings

Topological transition persists despite dephasing.

Numerical simulations confirm robustness against decay and dephasing.

Potential for higher-dimensional extensions in circuit QED.

Abstract

We extend the non-Hermitian one-dimensional quantum walk model [Phys. Rev. Lett. 102, 065703 (2009)] by taking the dephasing effect into account. We prove that the feature of topological transition does not change even when dephasing between the sites within units is present. The potential experimental observation of our theoretical results in the circuit QED system consisting of superconducting qubit coupled to a superconducting resonator mode is discussed and numerically simulated. The results clearly show a topological transition in quantum walk and display the robustness of such a system to the decay and dephasing of qubits. We also discuss how to extend this model to higher dimension in the circuit QED system.