Utilization of the spatial degree of freedom vastly enhances informational capacity of light at the cost of stringent requirements on the processing devices. Multi-mode quantum memories constitute a viable candidate for quantum and classical information processing; however, full utilization of the assets of high-dimensionality requires a flexible processing technique. We employ a spatially varying ac-Stark effect to perform arbitrary 1D phase modulation of a coherent spin-wave state stored in a wavevector-multiplexed quantum memory. A far-field and an interferometric near-field characterizations of the introduced phase profiles are presented. Additionally, coherence between temporally separated partial readouts of a single coherent spin-wave state is demonstrated, offering possible applications in adaptive measurements via conditional spin-wave modulation.
@article{arxiv.1902.07255,
title = {Spatial spin-wave modulator for quantum memory assisted adaptive measurements},
author = {Michał Lipka and Adam Leszczyński and Mateusz Mazelanik and Michał Parniak and Wojciech Wasilewski},
journal= {arXiv preprint arXiv:1902.07255},
year = {2019}
}