Toward a multi-core ultra-fast optical quantum processor: 43-GHz bandwidth real-time amplitude measurement of 5-dB squeezed light using modularized optical parametric amplifier with 5G technology
Toward a multi-core ultra-fast optical quantum processor: 43-GHz bandwidth real-time amplitude measurement of 5-dB squeezed light using modularized optical parametric amplifier with 5G technology
复制标题
DOI：
10.1063/5.0137641
复制
发表时间：
2023-03-06
影响因子：
4
通讯作者：
Furusawa, A.
中科院分区：
文献类型：
--
作者：
Inoue, A.;Kashiwazaki, T.;Furusawa, A.
连续变量光量子信息处理，其中量子信息被编码在称为飞行量子比特的光的行波中，是具有高时钟频率的实用量子计算机的候选者。用于正交相位幅度测量的同差检波器一直是限制时钟频率的主要因素。在这里，我们开发了一种使用模块化光参量放大器（OPA）和宽带平衡光电二极管的实时幅度测量方法，该方法用于第五代移动通信系统（5G）的相干波分复用通信。OPA将量子级信号的一个正交相位分量放大到可容忍损耗的宏观水平，并将OPA后的损耗从92.4%抑制到仅0.4%。该方法应用于中心波长为1545.32 nm的宽带压缩真空测量。在时域测量中，采用采样率为160 GHz、模拟带宽为63 GHz的实时示波器，获得了不含损耗校正的5.1 +/- 0.1 dB的压缩电平。频域分析还表明，从直流到43 GHz的压缩电平为5.2 +/- 0.5 dB，受平衡检测器的限制。这表明，通过使用更宽的带宽测量仪器，可以很容易地扩大所提出的方法。应用该方法不仅可以实现高时钟频率的光量子计算机，而且可以实现多核系统。(c) 2023作者。
Continuous-variable optical quantum information processing, where quantum information is encoded in a traveling wave of light called a flying qubit, is a candidate for a practical quantum computer with high clock frequencies. Homodyne detectors for quadrature-phase amplitude measurements have been the major factor limiting the clock frequency. Here, we developed a real-time amplitude measurement method using a modular optical parametric amplifier (OPA) and a broadband balanced photodiode that is commercially used for coherent wavelength-division multiplexing telecommunication of the fifth-generation mobile communication systems (5G). The OPA amplifies one quadrature-phase component of the quantum-level signal to a loss-tolerant macroscopic level and suppresses the loss after the OPA from 92.4% to only 0.4%. This method was applied to a broadband squeezed vacuum measurement with a center wavelength of 1545.32 nm. In the time-domain measurement, the squeezing level of 5.1 +/- 0.1 dB without loss correction was obtained by a real-time oscilloscope with a sampling rate of 160 GHz and an analog bandwidth of 63 GHz. The frequency-domain analysis also shows that a squeezing level of 5.2 +/- 0.5 dB is obtained from DC to 43 GHz, which is limited by the balanced detector. This indicates that the proposed method can be easily broadened by using a broader bandwidth measurement instrument. By applying this method, not only can optical quantum computers with high clock frequencies be realized but also multi-core systems can be realized.(c) 2023 Author(s).