Quantum metrology in different environments and experimental verification by quantum simulation

Quantum metrology based on quantum entanglement and quantum coherence improves the accuracy of measurements． This paper briefly reviews schemes of quantum metrology in various complex environments, including non-Markovian noise, correlated noise, and two-photon relaxation． The booming development of quantum information allows one to utilize quantum simulation experiments to test the feasibility of various theoretical schemes and demonstrate the rich physical phenomena in different baths．