Abstract
An obstacle for precision improvement in quantum metrology is the information loss causing by the unavoidable interaction between probe system and environment. Quantum fluctuations are environment no system can be isolated from and it will make the precision of initial parameter estimation of the probe atom decrease with time. After the typical time of the spontaneous decay of the probe atom, the precision is greatly damaged. However, quantum fluctuations can be modified. Our results show that if we put several ancillary atoms beside the probe atom in symmetrical arrangement, the probe atom will be affected by the ancillary atoms indirectly and the information loss of the probe atom causing by the quantum fluctuations will be partially avoided. We find that the retained precision after long time evolution can approaches to tfrac{{bf{9}}}{{bf{16}}} times of the initial precision in condition that the probe atom and three ancillary atoms are located in the vertex of regular tetrahedron.
Highlights
In estimation theory, parameter can be estimated from probability distribution and the Cramér-Rao bound[1, 2] tells us there exists uncertainty in parameter estimation
The precision limits of estimating initial atomic parameters decay with time and after the typical time of the spontaneous decay of the probe atom, the precision is greatly damaged[40]
If we put several ancillary atoms beside the probe atom, since all atoms are in interaction with the quantum fluatuations, the probe atom will be affected by the ancillary atoms indirectly and the information loss of the probe atom causing by the quantum fluctuations will be modified
Summary
An obstacle for precision improvement in quantum metrology is the information loss causing by the unavoidable interaction between probe system and environment. In reality, the probe systems are unavoidably in interaction with the environment, the quantum decoherence caused by the environment may decrease the QFI as well as destroy the quantum entanglement in the probe system exploited to improve the precision. In this regard, the dynamics of the estimation precision induced by the interaction between different models of system and environment have been studied[20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39]. As the indirect correlations of atoms are determined by the relative arrangement of the atoms, we may wonder what kind of arrangement will help us reduce the information loss and how much will the precision be retained
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
