Optical spin control and coherence properties of acceptor bound holes in strained GaAs
Optical spin control and coherence properties of acceptor bound holes in strained GaAs
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DOI：
10.1103/physrevb.103.115412
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发表时间：
2020-12
期刊：
影响因子：
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通讯作者：
X. Linpeng;T. Karin;M. Durnev;M. Glazov;R. Schott;A. Wieck;A. Ludwig;K. Fu
中科院分区：
文献类型：
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作者：
X. Linpeng;T. Karin;M. Durnev;M. Glazov;R. Schott;A. Wieck;A. Ludwig;K. Fu
半导体中的空穴自旋是电子自旋的潜在替代品。在像砷化镓这样的富含核自旋的宿主晶体中，空穴自旋与原子核的超精细相互作用要比电子弱得多，这可能导致更长的相干时间。在这里，我们展示了应变砷化镓外延层中受体结合孔的光泵浦和相干种群捕获。我们得到了$\mu$ s尺度纵向自旋弛豫时间T $_1$和$\sim$ 7 ns的非均匀消相时间T $_2^*$。我们将自旋弛豫机制归因于通过变形势的空穴-声子相互作用和面内磁场中重空穴-光空穴混合的组合效应。我们将短T $_2^*$归因于应变不均匀性导致的g因子展宽。根据这些机理定量计算了T $_1$和T $_2^*$，并与实验结果进行了比较。虽然超精细介导的退相干得到了缓解，但我们的研究结果强调了应变对受体结合的空穴自旋的弛豫和消相的重要贡献。
Hole spins in semiconductors are a potential qubit alternative to electron spins. In nuclear-spin-rich host crystals like GaAs, the hyperfine interaction of hole spins with nuclei is considerably weaker than that for electrons, leading to potentially longer coherence times. Here we demonstrate optical pumping and coherent population trapping for acceptor-bound holes in a strained GaAs epitaxial layer. We find $\mu$s-scale longitudinal spin relaxation time T$_1$ and an inhomogeneous dephasing time T$_2^*$ of $\sim$7~ns. We attribute the spin relaxation mechanism to a combination effect of a hole-phonon interaction through the deformation potentials and a heavy-hole light-hole mixing in an in-plane magnetic field. We attribute the short T$_2^*$ to g-factor broadening due to strain inhomogeneity. T$_1$ and T$_2^*$ are quantitatively calculated based on these mechanisms and compared with the experimental results. While the hyperfine-mediated decoherence is mitigated, our results highlight the important contribution of strain to relaxation and dephasing of acceptor-bound hole spins.