The energy of the signal, retrieved 100μs later by spin-echo techniques, reaches 0.3% of the energy absorbed by the spins, and this storage efficiency is quantitatively accounted for by simulations. This figure of merit is sufficient to envision first implementations of a quantum memory for superconducting qubits.
Storage and retrieval of microwave fields at the single-photon level in a spin ensemble
We report the storage of microwave pulses at the single-photon level in a spin-ensemble memory consisting of 1010 NV centers in a diamond crystal coupled to a superconducting LC resonator.