Switching effect in spin field-effect transistors

Abstract

We study how the conductance of a spin field-effect transistor (SFET) is manipulated by spin-orbit coupling strength, interfacial barrier height, and spin polarization in source and drain. It is shown that the conductance of the SFET exhibits an excellent switching characteristic for high potential barriers. By tuning the split-gate voltage one can vary the Dresselhaus [Phys. Rev. 100, 580 (1955)] spin-orbit coupling strength so as to switch the SFET on or off. On the other hand, in the SFET with almost Ohmic-contact interfaces there is pronounced conductance modulation mainly due to the Rashba [Sov. Phys. Solid State 2, 1190 (1960)] and Dresselhaus spin precession.