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Spin Relaxation Of “Upstream” Electrons In Quantum Wires: Failure Of The Drift Diffusion Model, Sandipan Pramanik, Supriyo Bandyopadhyay, Marc Cahay

Electrical and Computer Engineering Publications

The classical drift diffusion (DD) model of spin transport treats spin relaxation via an empirical parameter known as the “spin diffusion length.” According to this model, the ensemble averaged spin of electrons drifting and diffusing in a solid decays exponentially with distance due to spin dephasing interactions. The characteristic length scale associated with this decay is the spin diffusion length. The DD model also predicts that this length is different for “upstream” electrons traveling in a decelerating electric field than for “downstream” electrons traveling in an accelerating field. However, this picture ignores energy quantization in confined systems (e.g., quantum wires) …