Spin-polarized Zener tunneling in (Ga,Mn)As

Abstract

We investigate spin-polarized inter-band tunneling through measurement of a (Ga,Mn)As based Zener tunnel diode. By placing the diode under reverse bias, electron spin polarization is transferred from the valence band of p-type (Ga,Mn)As to the conduction band of an adjacent n-GaAs layer. The resulting current is monitored by injection into a quantum well light emitting diode whose electroluminescence polarization is found to track the magnetization of the (Ga,Mn)As layer as a function of both temperature and magnetic field.

Spintronics: Fundamentals and applications

“…115 Several spin diodes have recently been proposed or demonstrated with the goal of either maximizing the sensitivity of the I-V characteristics to spin and magnetic field, or facilitating spin injection and its detection through semiconductor interfaces comprising a magnetic semiconductor as the injector. Magnetic tunneling diodes have been used for spin injection from a ferromagnetic to a nonmagnetic semiconductor, in p-GaMnAs/n-GaAs p-n junctions (Kohda et al, 2001;Johnston-Halperin et al, 2002;Van Dorpe, Liu, et al, 2003). As discussed in Sec.…”

“…52 Tunneling or field emission becomes important, for example, in thin Schottky barriers or in p-n junctions and heterostructures at large reverse biases (Kohda et al, 2001;Johnston-Halperin et al, 2002;Van Dorpe, Liu, et al, 2003). 53 Equilibrium magnetization can be a consequence of doping with magnetic impurities, yielding large carrier g factors, and applying magnetic field, or of using a ferromagnetic semiconductor Pearton et al, 2003).…”

Surface treatments and magnetic properties of Ga1−xMnxAs thin films

“…In recent times a Curie temperature as high as 250 K [2] was obtained with delta-doped samples and moreover it was predicted [3] that carefully designed layered structure could have T c up to 350 K. Efficient spin injection was proved to be effective in a (Ga,Mn)As based heterostructure [4] and current driven magnetization reversal was also realized [5]. These advances are not supported by a similar knowledge on (Ga,Mn)As surface, which still lacks reliable cleaning and preparation protocols to obtain pure and ordered surfaces.…”

Voltage-controlled spin injection in a(Ga,Mn)As∕(Al,Ga)Dorpe1, Roy2, Boeck3 et al. 2005Phys. Rev. B

“…It has been shown that interband (Zener) tunneling from valence band electrons of (Ga,Mn)As to the conduction band of GaAs is a way to circumvent this disadvantage. 2,3 Recently, an injected spin polarization up to 80% at 4.6 K has been demonstrated in a (Ga,Mn)As based spin-light emitting diode (LED) using Zener tunneling. 4 Moreover, the degree of injected spin polarization exhibits a strong dependence on the applied bias.…”