Transfer of Entanglement from a Gaussian Field to Remote Qubits

Paulo José dos Reis, Santosh Shelly Sharma, Naresh Kumar Sharma

Paulo José dos Reis, S. Shelly Sharma, Naresh Kumar Sharma

Dynamics of entanglement transfer from two-mode squeezed field and initially entangled atomic qubit pair to atomic qubits located in remote cavities is examined. Remote qubits become entangled through interaction with two mode squeezed light.

Mai-Lin Liang, Bing Yuan, Jianan Zhang

Farhan Saif, Sami Ul Haq

Yanqiang Guo, Jie Li, Tiancai Zhang +1 more

The transfer of entanglement from optical fields to qubits provides a viable approach to entangling remote qubits in a quantum network. In cavity quantum electrodynamics, the scheme relies on the interaction between a photonic resource and two stationary intracavity atomic qubits. However, it might be hard in practice to trap two atoms simultaneously and synchronize their coupling to the cavities. To address this point, we propose and study entanglement transfer from cavities driven by an entangled external field to controlled flying qubits. We consider two exemplary non-Gaussian driving fields: NOON and entangled coherent states. We show that in the limit of long coherence time of the cavity fields, when the dynamics is approximately unitary, entanglement is transferred from the driving field to two atomic qubits that cross the cavities. On the other hand, a dissipation-dominated dynamics leads to very weakly quantum-correlated atomic systems, as witnessed by vanishing quantum discord.

Mauro Paternostro, Wonmin Son, M. S. Kim +2 more

A key element in the architecture of a quantum-information processing network is a reliable physical interface between fields and qubits. We study a process of entanglement transfer engineering, where two remote qubits respectively interact with an entangled two-mode continuous-variable (CV) field. We quantify the entanglement induced in the qubit state at the expenses of the loss of entanglement in the CV system. We discuss the range of mixed entangled states which can be obtained with this setup. Furthermore, we suggest a protocol to determine the residual entangling power of the light fields inferring, thus, the entanglement left in the field modes which, after the interaction, are no longer in a Gaussian state. Two different setups are proposed: a cavity-QED system and an interface between superconducting qubits and field modes. We address in detail the practical difficulties inherent in these two proposals, showing that the latter is promising in many aspects.