Hole spin relaxation in Ge-Si core-shell nanowire qubits
Hole spin relaxation in Ge-Si core-shell nanowire qubits
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DOI：
10.1038/nnano.2011.234
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发表时间：
2012-01-01
影响因子：
38.3
通讯作者：
Marcus, Charles M.
中科院分区：
文献类型：
--
作者：
Hu, Yongjie;Kuemmeth, Ferdinand;Marcus, Charles M.
控制退相干是开发量子信息硬件的最大挑战(1-3)。砷化镓中的单电子自旋是固态量子比特实现中的主要候选者，但它们与核自旋的强耦合产生高退相干率(4-6)。另一方面，第四族半导体具有相对较低的核自旋密度，这使得它们成为自旋量子位的有吸引力的平台。然而，器件制造仍然是一个挑战，特别是在材料和界面的控制方面(7)。在这里，我们演示了状态准备、脉冲栅极控制和限制在 Ge-Si 核壳纳米线中的空穴自旋的电荷传感自旋读出。通过快速选通，我们在零磁场下测量耦合量子点中高达 0.6 ms 的 T-1 自旋弛豫时间。弛豫时间随着磁场的减小而增加，这与通常被超精细贡献所掩盖的自旋轨道机制一致。
Controlling decoherence is the biggest challenge in efforts to develop quantum information hardware(1-3). Single electron spins in gallium arsenide are a leading candidate among implementations of solid-state quantum bits, but their strong coupling to nuclear spins produces high decoherence rates(4-6). Group IV semiconductors, on the other hand, have relatively low nuclear spin densities, making them an attractive platform for spin quantum bits. However, device fabrication remains a challenge, particularly with respect to the control of materials and interfaces(7). Here, we demonstrate state preparation, pulsed gate control and charge-sensing spin readout of hole spins confined in a Ge-Si core-shell nanowire. With fast gating, we measure T-1 spin relaxation times of up to 0.6 ms in coupled quantum dots at zero magnetic field. Relaxation time increases as the magnetic field is reduced, which is consistent with a spin-orbit mechanism that is usually masked by hyperfine contributions.