Future multi-photon applications of quantum optics and quantum information science require quantum memories that simultaneously store many photon states, each encoded into a different optical mode, and enable one to select the mapping between any input and a specific retrieved mode during storage. Here we show, with the example of a quantum repeater, how to employ spectrally-multiplexed states and memories with fixed storage times that allow such mapping between spectral modes. Furthermore, using a Ti:Tm:LiNbO3 waveguide cooled to 3 Kelvin, a phase modulator, and a spectral filter, we demonstrate storage followed by the required feed-forward-controlled frequency manipulation with time-bin qubits encoded into up to 26 multiplexed spectral modes and 97% fidelity.
@article{arxiv.1309.3202,
title = {Spectral multiplexing for scalable quantum photonics using an atomic frequency comb quantum memory and feed-forward control},
author = {Neil Sinclair and Erhan Saglamyurek and Hassan Mallahzadeh and Joshua A. Slater and Mathew George and Raimund Ricken and Morgan P. Hedges and Daniel Oblak and Christoph Simon and Wolfgang Sohler and Wolfgang Tittel},
journal= {arXiv preprint arXiv:1309.3202},
year = {2014}
}