论文标题
通过两个光子减法对挤压状态的多步三拷贝蒸馏
Multi-step two-copy distillation of squeezed states via two photon subtraction
论文作者
论文摘要
挤压状态一直在提高引力波观测值的敏感性，并且是量子加密和设想的光子量子计算机的非经典资源。挤压因子越高，量子优势越高。挤压光的几乎所有应用都需要多路径的光学干扰，其不可避免的缺陷会引入光学损失，降低挤压因子以及量子优势。在这里，我们第一次实验表明了高斯光子损失的高斯挤压状态的蒸馏。我们的演示已经涉及两个蒸馏步骤。第一步通过两个光子的减法将挤压系数从2.4 dB提高到2.8 dB。第二步通过高斯协议将值从2.8 dB提高到3.4 dB。它是在通过8端口平衡同源探测器和数据后处理在不同时间测量的数据实现的。蒸馏步骤的数量可以增加更长的数据采样时间，而无需其他硬件。我们建议并讨论量子密码学和光子量子计算机的应用。
Squeezed states of light have been improving the sensitivity of gravitational-wave observatories and are nonclassical resources of quantum cryptography and envisioned photonic quantum computers. The higher the squeeze factor is, the higher is the quantum advantage. Almost all applications of squeezed light require multi-path optical interference, whose unavoidable imperfections introduce optical loss, degrade the squeeze factor, as well as the quantum advantage. Here, for the first time, we experimentally demonstrate the distillation of Gaussian squeezed states that suffered from Gaussian photon loss. Our demonstration already involves two distillation steps. The first step improved the squeeze factor from 2.4 dB to 2.8 dB by the subtraction of two photons. The second step improved the value from 2.8 dB to 3.4 dB by a Gaussification protocol. It was realised on data measured at different times via an 8-port balanced homodyne detector and via data post-processing. The number of distillation steps can be increased by longer data sampling times, without additional hardware. We propose and discuss the application to quantum cryptography and photonic quantum computers.
