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arXiv · 1512.05740

Optical $π$ Phase Shift Created with a Single-Photon Pulse

Daniel Tiarks·Steffen Schmidt·Gerhard Rempe·Stephan Dürr
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Abstract

A deterministic photon-photon quantum-logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of $π$ onto another light field. Here we experimentally demonstrate the generation of such a $π$ phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse which propagates through the medium. Postselected on the detection of a retrieved photon from the first pulse, we measure a $π$ phase shift of the second pulse. This demonstrates a crucial step toward a photon-photon gate and offers a variety of applications in the field of quantum information processing.

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Daniel Tiarks, Steffen Schmidt, Gerhard Rempe, Stephan Dürr. 2016-04-29. Optical $π$ Phase Shift Created with a Single-Photon Pulse. https://doi.org/10.1126/sciadv.1600036

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