Generation and control of spin-polarized photocurrents in GaMnAs heterostructures

• Published in: Applied physics letters Vol. 104; no. 2
• Main Authors: Bezerra, Anibal T., Castelano, Leonardo K., Degani, Marcos H., Maialle, Marcelo Z., Farinas, Paulo F., Studart, Nelson
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 13-01-2014
• Subjects: Applied physics; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ENERGY SPECTRA; GALLIUM ARSENIDES; Heterostructures; MANGANESE ARSENIDES; PHOTOCURRENTS; PHOTONS; Polarization (spin alignment); SPIN; SPIN ORIENTATION
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4861656

Photocurrents are calculated for a specially designed GaMnAs semiconductor heterostructure. The results reveal regions in the infrared range of the energy spectrum, in which the proposed structure is remarkably spin-selective. For such photon energies, the generated photocurrents are strongly spin-polarized. Application of a relatively small static bias in the growth direction of the structure is predicted to efficiently reverse the spin-polarization for some photon energies. This behavior suggests the possibility of conveniently simple switching mechanisms. The physics underlying the results is studied and understood in terms of the spin-dependent properties emerging from the particular potential profile of the structure.