Parameter estimation in memory-assisted noisy quantum interferometry

P. Szańkowski, M. Trippenbach, J. Chwedeńczuk
2014 Physical Review A. Atomic, Molecular, and Optical Physics  
We demonstrate that memory in an N-qubit system subjected to decoherence, is a potential resource for the slow-down of the entanglement decay. We show that this effect can be used to retain the sub shot-noise sensitivity of the parameter estimation in quantum interferometry. We calculate quantum Fisher information, which sets the ultimate bound for the precision of the estimation. We also derive the sensitivity of such a noisy interferometer, when the phase is either estimated from the
more » ... nts of the population imbalance or from the one-body density.
doi:10.1103/physreva.90.063619 fatcat:t2bw22vo45h7zbvbd3cjdo3wfu