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arXiv · 1604.04278

A passive CPHASE gate via cross-Kerr nonlinearities

Daniel J. Brod·Joshua Combes
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Abstract

A fundamental and open question is whether cross-Kerr nonlinearities can be used to construct a controlled-phase (CPHASE) gate. Here we propose a gate constructed from a discrete set of atom-mediated cross-Kerr interaction sites with counter-propagating photons. We show that the average gate fidelity $F$ between a CPHASE and our proposed gate increases as the number of interaction sites increases and the spectral width of the photon decreases, e.g. with 12 sites we find $F > 99\%$.

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Daniel J. Brod, Joshua Combes. 2016-08-19. A passive CPHASE gate via cross-Kerr nonlinearities. https://doi.org/10.1103/physrevlett.117.080502

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