Confirmation of Mesoscopic Spin Transport in InGaAs Quantum Wells

对于InP晶格匹配的InGaAs量子阱，我们定量地揭示了零场自旋分裂项。我们不仅首次证明了长期以来一直是争议目标的拉什巴术语的存在，而且还成功地从数量上阐明了其大小。更具体地说，我们从理论上分析了稀磁电导数据中的微弱反局域化效应，首次给出了Rashba系数α与势垒内电场之间的线性关系。此外，我们还发现该系统中的Dresselhaus项很小。最后，我们还测量了介观环形阵列结构中的时间反转量子干涉效应，并从理论上证明了半经典方法的有效性。

For InP-lattice-matched InGaAs quantum wells, we have quantitatively revealed the zero-field spin splitting term. Not only in showing the presence of the Rashba term for the first time which has been the target of controversy for long time, but also we have succeeded in elucidating its size quantitatively. More specifically, we have shown for the first time the linear relation between the Rashba coefficient alpha and the electric field inside the well <Ez> from the theoretical analysis of the weak antilocalization effect that is seen in the magneto-conductivity data at dilution temperatures. In addition, we have found that the Dresselhaus term in this system is very small. Finally, we have also measured the time-reversal quantum interference effect in a mesoscopic loop array structure that is fabricated in a wafer whose <Ez> can be varied across zero by gate and demonstrated the effectiveness of the semi-classical approach in theory.