Phase tracking for sub-shot-noise-limited receivers
Phase tracking for sub-shot-noise-limited receivers
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DOI：
10.1103/physrevresearch.2.023384
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发表时间：
2020-06-23
影响因子：
4.2
通讯作者：
Becerra, F. E.
中科院分区：
文献类型：
--
作者：
DiMario, M. T.;Becerra, F. E.
基于诸如光子计数的非高斯测量的用于相位相干态的非常规接收器超过散粒噪声限制相干接收器的灵敏度极限，量子噪声极限（QNL）。这些非高斯接收机可以在未来的相干通信技术中产生重大影响。然而，在现实的通信信道，如光纤，随机相位变化，提出了严重的挑战，提取编码在相干态的信息。虽然存在用于利用常规外差检测来校正随机相位噪声的方法，但是用于超过QNL的非高斯接收器的相位跟踪仍然是一个开放的问题。在这里，我们演示了非高斯接收器的相位跟踪，以校正时变相位噪声，同时允许超出QNL的解码。相位跟踪方法利用非高斯鉴别测量的数据进行实时参数估计和相位漂移校正，而不依赖于相位参考导频场。这种方法使非高斯接收机在具有时变相位噪声的实际信道中获得比理想相干接收机更高的灵敏度和信息传输速率。该演示使子QNL接收器成为经典和量子通信的更强大，可行和实用的量子技术。
Nonconventional receivers for phase-coherent states based on non-Gaussian measurements such as photon counting surpass the sensitivity limits of shot-noise-limited coherent receivers, the quantum noise limit (QNL). These non-Gaussian receivers can have a significant impact in future coherent communication technologies. However, random phase changes in realistic communication channels, such as optical fibers, present serious challenges for extracting the information encoded in coherent states. While there are methods for correcting random phase noise with conventional heterodyne detection, phase tracking for non-Gaussian receivers surpassing the QNL is still an open problem. Here we demonstrate phase tracking for non-Gaussian receivers to correct for time-varying phase noise while allowing for decoding beyond the QNL. The phase-tracking method performs real-time parameter estimation and correction of phase drifts using the data from the non-Gaussian discrimination measurement, without relying on phase reference pilot fields. This method enables non-Gaussian receivers to achieve higher sensitivities and rates of information transfer than ideal coherent receivers in realistic channels with time-varying phase noise. This demonstration makes sub-QNL receivers a more robust, feasible, and practical quantum technology for classical and quantum communications.