Nonuniform current and spin accumulation in a 1 mu m thick n-GaAs channel

作者：Endres B^*; Ciorga M; Wagner R; Ringer S; Utz M; Bougeard D; Weiss D; Back C H; Bayreuther G

来源：Applied Physics Letters, 2012, 100(9): 092405.

DOI：10.1063/1.3691175

• current density
• gallium arsenide
• Hanle effect
• III-V semiconductors
• numerical analysis
• spin dynamics
• spin polarised transport

The spin accumulation in a n-GaAs channel produced by spin extraction into a (Ga,Mn)As contact is measured by cross-sectional imaging of the spin polarization in GaAs. The spin polarization is observed in a 1 mu m thick n-GaAs channel with the maximum polarization near the contact edge opposite to the maximum current density. The one-dimensional model of electron drift and spin diffusion, frequently used, cannot explain this observation. It also leads to incorrect spin lifetimes from Hanle curves with a strong bias and distance dependence. Numerical simulations based on a two-dimensional drift-diffusion model, however, reproduce the observed spin distribution quite well and lead to realistic spin lifetimes.

• 出版日期2012-2-27