[Publication] Recombination time mismatch and spin dependent photocurrent at a ferromagnetic-metal-semiconductor tunnel junction

Our researchers reported on carrier dynamics in a spin photodiode based on a ferromagnetic-metal–GaAs tunnel junction.

They showed that the helicity-dependent current is determined not only by the electron spin polarization and spin asymmetry of the tunneling but in great part by a dynamical factor resulting from the competition between tunneling and recombination in the semiconductor, as well as by a specific quantity: the charge polarization of the photocurrent.

The two latter factors can be efficiently controlled through an electrical bias. Under longitudinal magnetic field, they observed a strong increase of the signal arising from inverted Hanle effect, which is a fingerprint of its spin origin.

Thisapproach represents a radical shift in the physical description of this family of emerging spin devices.

Title: Recombination times mismatch and spin dependent photocurrent at a ferromagnetic-metal/semiconductor tunnel junction

Authors: Viatcheslav I. Safarov, Igor V. Rozhansky, Ziqi Zhou, Bo Xu, Zhong-Ming Wei, Zhan-Guo Wang, Yuan Lu, Henri Jaffès and Henri-Jean Drouhin

Journal: Physical Review Letters

Date of publication (online): February 2022

Link: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.057701

Image caption: Design of the perpendicular-magnetization spin photodiode