Quantum Memory in An Eu:YSO Crystal for Polarization and Time-Bin Qubit States
摘要
We demonstrate the storage and readout of the polarization state of light with a memory based on the atomic frequency comb protocol in a 153Eu:Y2SiO5 crystal, both in the bright-pulse regime and at the single photon level. We reconstruct the χ-matrix of the process corresponding to our quantum memory and demonstrate the recall fidelity for the quantum state of about 80% at the maximum efficiency of about 26%. It is also shown that the quantum memory stores the phase difference between the stored pulses with high fidelity, which is essential for working with time-bin qubits.