Spin-dependent photoelectron tunneling from GaAs into magnetic cobalt
Abstract
The spin dependence of the photoelectron tunnel current from free standing GaAs films into outof-plane magnetized Cobalt films is demonstrated. The measured spin asymmetry (A) resulting from a change in light helicity, reaches ±6% around zero applied tunnel bias and drops to ±2% at a bias of -1.6 V applied to the GaAs. This decrease is a result of the drop in the photoelectron spin polarization that results from a reduction in the GaAs surface recombination velocity. The sign of A changes with that of the Cobalt magnetization direction. In contrast, on a (nonmagnetic) Gold film A ≈ 0%.
Domains
Condensed Matter [cond-mat]
Origin : Files produced by the author(s)