Improving the sensitivity of distributed phase estimation under noisy Gaussian environment with noiseless linear amplification

Abstract

The deterioration of precision caused by quantum decoherence in dissipative environments is a longstanding problem in the development of distributed quantum metrology. Therefore, it is significant to effectively overcome the entanglement-distribution loss and channel noise of dissipative environments and improve the measurement-sensitivity. Here, we introduce noiseless linear amplifier (NLA) based on photon catalysis into distributed phase estimation to mitigate the loss and noise. Through utilizing a series of reduction and equivalence relations to simplify the problem of distributed phase estimation to a single-parameter estimation situation, our results show that Photon catalysis (PC)-NLAs can effectively mitigate the loss and noise of dissipative environments, and greatly improve the measurement-sensitivity. More interestingly, we find that adding thermal photons of environment has positive contributions on the measurement-sensitivity under certain circumstances. Our scheme should prove valuable for the global wide-area quantum sensor network.