论文标题
基于光子辅助的准粒子隧道的超导量重置的初步实验结果
Initial experimental results on a superconducting-qubit reset based on photon-assisted quasiparticle tunneling
论文作者
论文摘要
我们在这里介绍了基于量子电路冰箱（QCR）的量子重置方案的最新结果。特别是，我们使用光子辅助的准粒子隧穿通过超导体 - 绝缘子 - 正常 - 金属 - 胰蛋白酶 - 螺旋传感器 - 螺旋杆连接来控制QCR操作期间QUB的能量放松时间。在我们的实验中，我们使用带有分散读数的Transmon Qubit。 QCR通过其正常的金属岛与量子轴相连。我们采用持续时间在2--350 ns和各种振幅范围内的快速，方形的QCR控制电压脉冲来优化重置时间和保真度。因此，我们达到量子态概率约为97％，从第一个激发态开始，80-ns脉冲。从平均读取信号中提取量子状态概率，其中校准基于拉比振荡，因此无法区分量子的残留热群体。
We present here our recent results on qubit reset scheme based on a quantum-circuit refrigerator (QCR). In particular, we use the photon-assisted quasiparticle tunneling through a superconductor--insulator--normal-metal--insulator--superconductor junction to controllably decrease the energy relaxation time of the qubit during the QCR operation. In our experiment, we use a transmon qubit with dispersive readout. The QCR is capacitively coupled to the qubit through its normal-metal island. We employ rapid, square-shaped QCR control voltage pulses with durations in the range of 2--350 ns and a variety of amplitudes to optimize the reset time and fidelity. Consequently, we reach a qubit ground-state probability of roughly 97% with 80-ns pulses starting from the first excited state. The qubit state probability is extracted from averaged readout signal, where the calibration is based of the Rabi oscillations, thus not distinguishing the residual thermal population of the qubit.
