Delayed transfer of entanglement to initially populated qubits

TL;DR

This paper investigates how the initial population of cavities affects the timing of entanglement transfer from a squeezed field, revealing a delay linked to quantum jumps and decay rates.

Contribution

It demonstrates that the transfer of quantum correlations is delayed by initial cavity populations and depends on cavity decay rates, highlighting the role of quantum jumps in this process.

Findings

Transfer of photons begins immediately after input is turned on.

Quantum correlation transfer is delayed if cavities are initially populated.

Delay depends on cavity decay rates and quantum jump dynamics.

Abstract

The transfer of entangled, quantum correlated, flying photons from a squeezed field to single-mode cavities is investigated. It is shown that, while the transfer of photons begins immediately after the input squeezed field is turned on, the time at which quantum correlations start to be transferred to the cavities is strongly dependent on the initial population of the cavities. For the initially empty cavities, the transfer of quantum correlations begins immediately after the squeezed field is turned on, but it is delayed by a certain time interval when the cavities are initially populated. We find that the transfer of the quantum correlations is postponed until the one-photon states of the system are almost completely depopulated. In other words, the system "waits" for the population of the single-photon states to decay out before starting to build up the quantum correlation between the cavities. The delay time interval is independent of the number of photons initially present in the system, but it is dependent on the decay rates of the cavities and can be varied (controlled) when the cavities decay with different rates. It is shown that the delayed transfer of the quantum correlation is directly related to the presence of quantum jumps, which transfer the population from the entangled to incoherent mixture states.