Quantum storage of 1650 modes of single photons at telecom wavelength

Abstract

To advance the full potential of quantum networks one should be able to distribute quantum resources over long distances at appreciable rates. As a consequence, all components in such networks need to have large multimode capacity to manipulate photonic quantum states. Towards this end, a photonic quantum memory with a large multimode capacity, especially one operating at telecom wavelength, remains an important challenge. Here we optimize the preparation of atomic frequency combs and demonstrate a spectro-temporally multiplexed quantum memory in a 10-m-long cryogenically cooled erbium doped silica fibre. Our multiplexing storage has five spectral channels - each 10 GHz wide with 5 GHz separation - with up to 330 temporal modes in each, thus resulting in a simultaneous storage of 1,650 modes of heralded single photons with a 1000-fold increasing in coincidence detection rate with respect to single mode storage. Our results could pave the way for high speed quantum networks compatible with the infrastructure of fibre optical communication.

Towards a realistic model for cavity-enhanced atomic frequency comb quantum memories

“…Atomic frequency comb (AFC) quantum memory [7,8] is a promising candidate in quantum repeater applications because of the capability to simultaneously store and read out multiple temporal and spectral modes that could enhance the performance of the quantum repeater via faster entanglement generation [9][10][11][12][13][14][15]. Also, as opposed to other quantum memory protocols, with the AFC technique, the number of temporal modes stored in a sample is independent of the optical depth of the storage medium [7].…”