TY - JOUR T1 - Photon Subtraction by Many-Body Decoherence Y1 - 2018 A1 - Callum R. Murray A1 - Ivan Mirgorodskiy A1 - Christoph Tresp A1 - Christoph Braun A1 - Asaf Paris-Mandoki A1 - Alexey V. Gorshkov A1 - Sebastian Hofferberth A1 - Thomas Pohl AB -

We present an experimental and theoretical investigation of the scattering-induced decoherence of multiple photons stored in a strongly interacting atomic ensemble. We derive an exact solution to this many-body problem, allowing for a rigorous understanding of the underlying dissipative quantum dynamics. Combined with our experiments, this analysis demonstrates a correlated coherence-protection process, in which the induced decoherence of one photon can preserve the spatial coherence of all others. We discuss how this effect can be used to manipulate light at the quantum level, providing a robust mechanism for single-photon subtraction, and experimentally demonstrate this capability.

UR - https://arxiv.org/abs/1710.10047 U5 - https://doi.org/10.1103/PhysRevLett.120.113601 ER - TY - JOUR T1 - Many-body decoherence dynamics and optimised operation of a single-photon switch JF - New Journal of Physics Y1 - 2016 A1 - Callum R. Murray A1 - Alexey V. Gorshkov A1 - Thomas Pohl AB -

We develop a theoretical framework to characterize the decoherence dynamics due to multi-photon scattering in an all-optical switch based on Rydberg atom induced nonlinearities. By incorporating the knowledge of this decoherence process into optimal photon storage and retrieval strategies, we establish optimised switching protocols for experimentally relevant conditions, and evaluate the corresponding limits in the achievable fidelities. Based on these results we work out a simplified description that reproduces recent experiments [arXiv:1511.09445] and provides a new interpretation in terms of many-body decoherence involving multiple incident photons and multiple gate excitations forming the switch. Aside from offering insights into the operational capacity of realistic photon switching capabilities, our work provides a complete description of spin wave decoherence in a Rydberg quantum optics setting, and has immediate relevance to a number of further applications employing photon storage in Rydberg media. 

VL - 18 U4 - 092001 UR - http://iopscience.iop.org/article/10.1088/1367-2630/18/9/092001 U5 - 10.1088/1367-2630/18/9/092001 ER -