Könemann J, Haug R J, Maude D K, Fal'ko V I, Altshuler B L
Institut für Festkörperphysik, Universität Hannover, Appelstrasse 2, D-30167 Hannover, Germany.
Phys Rev Lett. 2005 Jun 10;94(22):226404. doi: 10.1103/PhysRevLett.94.226404. Epub 2005 Jun 7.
In lateral quantum dots, the combined effect of both Dresselhaus and Bychkov-Rashba spin-orbit coupling is equivalent to an effective magnetic field +/- B(SO) which has the opposite sign for s(z)= +/- 1/2 spin electrons. When the external magnetic field is perpendicular to the planar structure, the field B(SO) generates an additional splitting for electron states as compared to the spin splitting in the in-plane field orientation. The anisotropy of spin splitting has been measured and then analyzed in terms of spin-orbit coupling in several AlGaAs/GaAs quantum dots by means of resonant tunneling spectroscopy. From the measured values and sign of the anisotropy we are able to determine the dominating spin-orbit coupling mechanism.
在横向量子点中，德雷塞尔豪斯（Dresselhaus）自旋轨道耦合和贝奇科夫 - 拉什巴（Bychkov - Rashba）自旋轨道耦合的联合效应等效于一个有效磁场±B(SO)，对于自旋s(z)=±1/2的电子，该磁场具有相反的符号。当外部磁场垂直于平面结构时，与面内磁场方向的自旋分裂相比，磁场B(SO)会使电子态产生额外的分裂。通过共振隧穿光谱法，在几个AlGaAs/GaAs量子点中测量并根据自旋轨道耦合分析了自旋分裂的各向异性。根据测量得到的各向异性值和符号，我们能够确定主导的自旋轨道耦合机制。
