Non-Gaussian state generation with time-gated photon detection

TL;DR

This paper demonstrates that time-gated photon detection significantly improves the purity of non-Gaussian states of light, crucial for quantum computing, by experimentally reducing timing jitter and observing Wigner negativity.

Contribution

It introduces a method using time gating to enhance non-Gaussian state generation, experimentally confirming the impact of timing jitter on state purity.

Findings

Achieved Wigner negativity of -0.011 with time gating

Reduced timing jitter from 50 ns to 10 ns

First experimental confirmation of jitter effect on non-Gaussian states

Abstract

Non-Gaussian states of light, which are essential in fault-tolerant and universal optical quantum computation, are typically generated by a heralding scheme using photon detectors. Recently, it is theoretically shown that the large timing jitter of the photon detectors deteriorates the purity of the generated non-Gaussian states [T. Sonoyama, $\textit{et al}$., Phys. Rev. A $\textbf{105}$, 043714 (2022)]. In this study, we generate non-Gaussian states with Wigner negativity by time-gated photon detection. We use a fast optical switch for time gating to effectively improve the timing jitter of a photon-number-resolving detector based on transition edge sensor from 50 ns to 10 ns. As a result, we generate non-Gaussian states with Wigner negativity of $-0.011\pm 0.004$, which cannot be observed without the time-gated photon detection method. These results confirm the effect of the timing jitter on non-Gaussian state generation experimentally for the first time and provide the promising method of high-purity non-Gaussian state generation.