论文标题
Transmon Qubit读数保真度在阈值的量子误差校正的情况下，没有量子限制的放大器
Transmon qubit readout fidelity at the threshold for quantum error correction without a quantum-limited amplifier
论文作者
论文摘要
量子状态的高保真性和快速读数是量子计算和通信的关键，它是进行量子误差校正的先决条件。我们提出了一种结合两种微波技术的超导量子台的读数方案：将搁架技术应用于有效增加能量扩张时间的量子，以及对读出谐振器的两色调激发，以区分较高能级的Qubit种群。使用机器学习算法进行后处理，两色调测量结果进一步改善了Qubit-State分配保真度。我们在140NS读数时间内执行单次频率 - 多头置量量读数，并在不使用量子限制放大器的情况下证明了两态读数的分配保真度为99.5％，三态读数的分配保真度为96.9％。
High-fidelity and rapid readout of a qubit state is key to quantum computing and communication, and it is a prerequisite for quantum error correction. We present a readout scheme for superconducting qubits that combines two microwave techniques: applying a shelving technique to the qubit that effectively increases the energy-relaxation time, and a two-tone excitation of the readout resonator to distinguish among qubit populations in higher energy levels. Using a machine-learning algorithm to post-process the two-tone measurement results further improves the qubit-state assignment fidelity. We perform single-shot frequency-multiplexed qubit readout, with a 140ns readout time, and demonstrate 99.5% assignment fidelity for two-state readout and 96.9% for three-state readout - without using a quantum-limited amplifier.
