Quantum Sensing with Topological-Paired Bound States

TL;DR

This paper introduces a robust quantum sensing protocol using topological-paired bound states in a waveguide system, achieving Heisenberg-limited sensitivity and robustness against perturbations, suitable for near-term quantum platforms.

Contribution

The paper proposes a novel quantum sensing method leveraging topological bound states, enabling high sensitivity and robustness with simple initial states.

Findings

Sensitivity reaches the Heisenberg limit.

Protocol is robust against local perturbations.

Uses easily prepared product states.

Abstract

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.