Closed-loop control of a GaAs-based singlet-triplet spin qubit with 99.5% gate fidelity and low leakage
Closed-loop control of a GaAs-based singlet-triplet spin qubit with 99.5% gate fidelity and low leakage
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DOI：
10.1038/s41467-020-17865-3
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发表时间：
2020-08-18
影响因子：
16.6
通讯作者：
Bluhm, Hendrik
中科院分区：
文献类型：
--
作者：
Cerfontaine, Pascal;Botzem, Tim;Bluhm, Hendrik
半导体自旋量子位最近在相干时间和控制精度方面取得了重大进展，从而使单量子位性能与其他领先的量子位平台不相上下。这些进展大部分是基于同位素纯化硅制成的设备中的单自旋的微波控制。为了控制自旋，交换相互作用是一个额外的关键因素，这对高保真控制提出了新的挑战。在这里，我们展示了基于交换的GaAs双量子点双电子自旋量子比特的单量子比特门。通过仔细的脉冲优化和闭环调谐，我们实现了（99.50 +/- 0.04）%的随机基准保真度和0.13%的计算子空间泄漏率。这些结果为GaAs和其他材料中单重态-三重态量子比特的微波无控制开辟了新的前景。
Semiconductor spin qubits have recently seen major advances in coherence time and control fidelities, leading to a single-qubit performance that is on par with other leading qubit platforms. Most of this progress is based on microwave control of single spins in devices made of isotopically purified silicon. For controlling spins, the exchange interaction is an additional key ingredient which poses new challenges for high-fidelity control. Here, we demonstrate exchange-based single-qubit gates of two-electron spin qubits in GaAs double quantum dots. Using careful pulse optimization and closed-loop tuning, we achieve a randomized benchmarking fidelity of (99.50 +/- 0.04)% and a leakage rate of 0.13% out of the computational subspace. These results open new perspectives for microwave-free control of singlet-triplet qubits in GaAs and other materials.