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arXiv 1906.04512cond-mat.mes-hallquant-ph
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利用谐振SWAP门实现硅中量子信息的相干传输

Coherent transfer of quantum information in silicon using resonant SWAP gates

A. J. Sigillito, M. J. Gullans, L. F. Edge, M. Borselli, J. R. Petta

摘要:

基于硅量子点自旋的固态量子处理器正在成为量子信息处理的强大平台。高保真度的单量子位和双量子位门最近已经被证明,大型可扩展量子位阵列现在被常规制造。然而,双量子比特门是通过最近邻交换相互作用介导的,这需要直接波函数重叠。这限制了这些设备的整体连接性,并且是实现纠错、量子随机存取存储器和多量子比特量子算法的主要障碍。为了扩展连接性,量子比特可以使用量子SWAP门在设备周围穿梭,但相位相干SWAP尚未在硅设备中实现。在这里,我们展示了一种新的单步谐振SWAP门。我们首先使用门来有效地初始化和读出我们的双量子点。然后,我们表明,门可以移动自旋本征态在100 ns的平均保真度$\bar{F}_{SWAP}^p$ = 98%。最后,任意两个量子比特的产品状态的转移基准使用状态断层扫描和Clifford随机基准,产生的平均保真度为$\bar{F}_{SWAP}^c$ = 84%的门操作时间为~300 ns。通过相干自旋输运,我们的共振SWAP门实现了非相邻量子比特的耦合,从而为使用硅自旋量子比特的大规模实验铺平了道路。

英文摘要:

Solid state quantum processors based on spins in silicon quantum dots are emerging as a powerful platform for quantum information processing. High fidelity single- and two-qubit gates have recently been demonstrated and large extendable qubit arrays are now routinely fabricated. However, two-qubit gates are mediated through nearest-neighbor exchange interactions, which require direct wavefunction overlap. This limits the overall connectivity of these devices and is a major hurdle to realizing error correction, quantum random access memory, and multi-qubit quantum algorithms. To extend the connectivity, qubits can be shuttled around a device using quantum SWAP gates, but phase coherent SWAPs have not yet been realized in silicon devices. Here, we demonstrate a new single-step resonant SWAP gate. We first use the gate to efficiently initialize and readout our double quantum dot. We then show that the gate can move spin eigenstates in 100 ns with average fidelity $\bar{F}_{SWAP}^p$ = 98%. Finally, the transfer of arbitrary two-qubit product states is benchmarked using state tomography and Clifford randomized benchmarking, yielding an average fidelity of $\bar{F}_{SWAP}^c$ = 84% for gate operation times of ~300 ns. Through coherent spin transport, our resonant SWAP gate enables the coupling of non-adjacent qubits, thus paving the way to large scale experiments using silicon spin qubits.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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