Enhancing the precision of a quantum Wheatstone bridge through reservoir engineering
Phys. Rev. A 113, 052214 – Published 14 May, 2026
DOI: https://doi.org/10.1103/svr9-186m
Abstract
Decoherence which describes the disappearance or absence of certain superpositions of quantum states can be employed as an essential tool in diverse quantum technologies. Following this line of thought, we propose a protocol aimed at enhancing the estimation precision of an unknown coupling strength in the quantum Wheatstone bridge in this paper. We consider the setup consisting of two interface spins, two outer spins, and two baths of different temperatures at each extremity. There are coherent interactions between nearest-neighboring spins, and a dissipative coupling between the two interface spins via an engineered shared reservoir. We identify the balance of the quantum Wheatstone bridge as the steady state of the system. When the controllable coupling approaches the unknown coupling, the population of the antisymmetric Bell state shows a sharp dip due to destructive interference, resulting in the state of the interface spins being highly sensitive to changes in the unknown coupling strength. Compared with the previous quantum Wheatstone bridge, the introduction of dissipative coupling significantly enhances the estimation precision of the unknown coupling strength. This work would open a different avenue for enhancing the precision through reservoir engineering and find applications in many fields, including precise measurement and quantum information science.
