Parameter estimation in a memory-assisted noisy quantum interferometry

Understand

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 measurements of the population imbalance or from the one-body density.