Bias-dependent electron spin lifetimes in n-GaAs and the role of donor impact ionization

Abstract

In bulk n-GaAs epilayers doped near the metal-insulator transition, we study the evolution of electron spin lifetime ${\tau }_s$ as a function of applied lateral electrical bias $E_x$. ${\tau }_s$ is measured via the Hanle effect using magneto-optical Kerr rotation. At low temperatures (T<10 K, where electrons are partially localized and ${\tau }_s>100$ ns at zero bias), a marked collapse of ${\tau }_s$ is observed when $E_x$ exceeds the donor impact ionization threshold at $\sim$10 V/cm. A steep increase in the concentration of warm delocalized electrons -- subject to Dyakonov-Perel spin relaxation -- accounts for the rapid collapse of ${\tau }_s$, and strongly influences electron spin transport in this regime.

4 pages, 3 figures

References in corpus (2)

• Electrical Detection of Spin Accumulation at a Ferromagnet-Semiconductor Interface
• Spin lifetimes and strain-controlled spin precession of drifting electrons in zinc blende type semiconductors

Cited by in corpus (5)

• Electrical Detection of Spin Transport in Lateral Ferromagnet-Semiconductor Devices
• Spin injection and detection up to room temperature in Heusler~alloy/$n$-GaAs spin valves
• Optical and electrical spin injection and spin transport in hybrid Fe/GaAs devices
• Electron charge and spin delocalization revealed in the optically probed longitudinal and transverse spin dynamics in $n$-GaAs
• Effect of electric current on optical orientation of electrons in AlGaAs/GaAs heterostructure