Eur. Phys. J. B (2012) 85: 298
https://doi.org/10.1140/epjb/e2012-30333-6

Regular Article

Interplay of Rashba- and Dresselhaus spin-orbit interactions in a quasi-two-dimensional electron gas of a finite thickness under in-plane magnetic field

¹ Institut für Theoretische Physik, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
² Institute of Physics, Azerbaijan National Academy of Sciences, H. Cavid str. 33, AZ 1143 Baku, Azerbaijan

^a e-mail: enver.nakhmedov@physik.uni-wuerzburg.de

Received: 19 April 2012
Received in final form: 2 July 2012
Published online: 5 September 2012

Abstract

Interplay of Rashba- and Dresselhaus spin-orbit interactions and in-plane magnetic field is studied in a quasi-two-dimensional electron gas with finite thickness. The transverse confinement is modeled by means of a parabolic potential. An orbital effect of the in-plane magnetic field is shown to mix a transverse quantized spin-up state with nearest-neighboring spin-down states. A controllable changes of the spin-orbital interactions, orbital- and Zeeman effects of the in-plane magnetic field yield a multivalley energy subbands, where a negative differential resistance can be observed. The out-off-plane component of the equilibrium spin current appears to be not zero in the presence of an in-plane magnetic field, provided at least two transverse-quantized levels are filled. In the absence of the magnetic field the obtained results coincide with the well-known results, yielding cubic dependence of the equilibrium spin current on the spin-orbit coupling constants. The persistent spin-current vanishes in the absence of the magnetic field if Rashba- and Dresselhaus spin-orbit coefficients, α and β, are equal each other. In-plane magnetic field destroys this symmetry, and yields a finite spin-current as α → β. Magnetic field is shown to change strongly the equilibrium current of the in-plane spin components, and gives new contributions to the cubic-dependent on spin-orbit constants terms. These new terms depend linearly on the spin-orbit constants.