We present an efficient and robust protocol for quantum-enhanced sensing using a single qubit in the topological waveguide system. Our method relies on the topological-paired bound states, which are localized near the qubit and can be effectively regarded as a two-level system. Through the lens of Bayesian inference theory, we show that the sensitivity can reach the Heisenberg limit across a large field range. Inheriting from the topological robustness of the waveguide, our sensing protocol is robust against local perturbations. Besides, our sensing protocol utilizes a product state as the initial state, which can be easily prepared in experiments. We expect this approach would pave the way toward robust topological quantum sensors based on near-term quantum platforms such as superconducting qubits and Rydberg arrays.
@article{arxiv.2311.01370,
title = {Quantum Sensing with Topological-Paired Bound States},
author = {Tao Zhang and Peng Xu and Jiazhong Hu and Xingze Qiu},
journal= {arXiv preprint arXiv:2311.01370},
year = {2025}
}