Distinct Three-Level Spin–Orbit Control Associated with Electrically Controlled Band Swapping
Yu Suo1,2†, Hao Yang1†, and Jiyong Fu1,3,4*
1Department of Physics, Qufu Normal University, Qufu 273165, China 2Department of Physics, Jining University, Qufu 273155, China 3Instituto de Fı́sica, Universidade de Brası́lia, Brası́lia-DF 70919-970, Brazil 4Collaborative Innovation Center of Light Manipulations and Applications, Shandong Normal University, Jinan 250358, China
Abstract：We investigate the Rashba and Dressehaus spin–orbit (SO) couplings in an ordinary GaAs/AlGaAs asymmetric double well, which favors the electron occupancy of three subbands $\nu=1,2,3$. Resorting to an external gate, which adjusts the electron occupancy and the well symmetry, we demonstrate distinct three-level SO control of both Rashba ($\alpha_\nu$) and Dresselhaus ($\beta_\nu$) {intraband} terms. Remarkably, as the gate varies, the first-subband SO parameters $\alpha_1$ and $\beta_1$ comply with the usual linear behavior, while $\alpha_2$ ($\beta_2$) and $\alpha_3$ ($\beta_3$) respectively for the second and third subbands interchange the values, triggered by a gate controlled band swapping. This provides a pathway towards fascinating selective SO control in spintronic applications. Moreover, we observe that the {interband} Rashba ($\eta_{\mu\nu}$) and Dresselhaus ($\varGamma_{\mu\nu}$) terms also exhibit contrasting gate dependence. Our results should stimulate experiments probing SO couplings in multi-subband wells and adopting relevant SO features in future spintronic devices.
Chuang P, Ho S, Smith L W, Sfigakis F, Pepper M, Chen C, Fan J, Griffiths J P, Farrer I, Beere H E, Jones G A C, Ritchie D A and Chen T 2015 Nat. Nanotechnol.10 35
2020, Vol. 37 
