Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku 113-8656, Japan.
Nat Nanotechnol. 2011 Jul 24;6(8):511-6. doi: 10.1038/nnano.2011.103.
Electrical control over electron spin is a prerequisite for spintronics spin-based quantum information processing. In particular, control over the interaction between the orbital motion and the spin state of electrons would be valuable, because this interaction influences spin relaxation and dephasing. Electric fields have been used to tune the strength of the spin-orbit interaction in two-dimensional electron gases, but not, so far, in quantum dots. Here, we demonstrate that electrical gating can be used to vary the energy of the spin-orbit interaction in the range 50-150 µeV while maintaining the electron occupation of a single self-assembled InAs quantum dot. We determine the spin-orbit interaction energy by observing the splitting of Kondo effect features at high magnetic fields.
电控制电子自旋是自旋电子学基于自旋的量子信息处理的前提。特别是，控制电子的轨道运动和自旋态之间的相互作用将是有价值的，因为这种相互作用会影响自旋弛豫和退相。电场已被用于调整二维电子气中自旋轨道相互作用的强度，但到目前为止，还没有用于量子点。在这里，我们证明电门控可以用于在保持单个自组装 InAs 量子点的电子占据的情况下，将自旋轨道相互作用的能量在 50-150 µeV 的范围内变化。我们通过观察在高磁场下 Kondo 效应特征的分裂来确定自旋轨道相互作用能量。
