论文标题
使用频率上转换技术评估飞秒时量量子A
Evaluation of Femtosecond Time-bin Qubits Using Frequency Up-conversion Technique
论文作者
论文摘要
时间键量量子位，其中量子信息在不同时间$δ$ t中编码在单个光子中，适用于通过光纤长途传输。然而，由于单光子检测器的时间分辨率有限，时间键量量子位的检测已限于纳秒范围。在这项研究中，我们使用具有不同长度的商业非线性晶体开发了近调单光子检测器（UCSPD）。通过更改晶体长度和泵功率，我们定量评估了UCSPD的效率和时间分辨率，并确定了测量飞秒时间二键量子量的最佳条件。该检测器的时间分辨率为415 fs，上转换效率为10.1％。因此，我们成功地评估了单光子级伪飞秒时键量子量，其脉冲间隔仅为800 fs。
Time-bin qubits, in which quantum information is encoded in a single photon at different times $Δ$t, are suitable for long-distance transmission via optical fibers. However, detection of time-bin qubits has been limited to the nanosecond range owing to the limited temporal resolution of single-photon detectors. In this study, we developed an up-conversion single-photon detector (UCSPD), using commercial nonlinear crystals of different lengths. By changing the crystal length and pump power, we quantitatively evaluated the efficiency and temporal resolution of the UCSPD and determined the optimal conditions for measuring femtosecond time-bin qubits. This detector achieved a temporal resolution of 415 fs and up-conversion efficiency of 10.1 %. Consequently, we successfully evaluated single-photon level pseudo femtosecond time-bin qubits with a pulse interval of only 800 fs.
