Pfund A, Shorubalko I, Ensslin K, Leturcq R
Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
Phys Rev Lett. 2007 Jul 20;99(3):036801. doi: 10.1103/PhysRevLett.99.036801. Epub 2007 Jul 16.
We investigate the triplet-singlet relaxation in a double quantum dot defined by top gates in an InAs nanowire. In the Pauli spin blockade regime, the leakage current can be mainly attributed to spin relaxation. While at weak and strong interdot coupling relaxation is dominated by two individual mechanisms, the relaxation is strongly reduced at intermediate coupling and finite magnetic field. In addition we observe a characteristic bistability of the spin-nonconserving current as a function of magnetic field. We propose a model where these features are explained by the polarization of nuclear spins enabled by the interplay between hyperfine and spin-orbit mediated relaxation.
我们研究了由InAs纳米线中的顶栅定义的双量子点中的三重态-单重态弛豫。在泡利自旋阻塞 regime中，泄漏电流主要可归因于自旋弛豫。虽然在弱和强点间耦合时弛豫由两种单独的机制主导，但在中间耦合和有限磁场下弛豫会显著降低。此外，我们观察到自旋非守恒电流作为磁场函数的特征双稳性。我们提出了一个模型，其中这些特征由超精细和自旋轨道介导的弛豫之间的相互作用所导致的核自旋极化来解释。
