Developing III-V spin optoelectronic devices operating at zero magnetic field

Spin optoelectronic devices (spin light-emitting diode, spin laser and spin photodiode), which can convert the carrier spin polarization with the photon circular polarization, have gained intensive interest in the last decade. The potential applications of spin optoelectronic device can be used for optical communication, 3D display, biomedical analyses, etc. However, the obstacles for developing these applications are relied on the room temperature operation and without applying the magnetic field. According to the optical selection rule, for surface emitting and detecting geometry, the conventional spin injector with in-plane magnetization requires a strong external magnetic field in the range of a few Tesla, which is impossible for the practical application. Since 2014, we have developed the spin injector with perpendicular magnetic anisotropy (PMA) consisting of an ultrathin CoFeB (1.2 nm)/MgO (2.5 nm) on GaAs based quantum well (QW) [1] and quantum dot (QD) LED [2]. In this talk, I will give a presentation on our progress on developing PMA spin injector with better thermal stability [3], the evidence of polarization of nuclei spin by electron spin [2], the understanding of spin relaxation mechanism in spin LED [4] and the developing of spin photodiode with PMA spin detector [5].