Spin oscillations in transient diffusion of a spin pulse in n-type semiconductor quantum wells

TL;DR

This paper investigates the transient behavior of spin pulses in n-type semiconductor quantum wells, revealing the critical role of off-diagonal spin coherence and predicting spin oscillations and reversals without external magnetic fields.

Contribution

It introduces the significance of off-diagonal spin coherence in spin diffusion and predicts novel spin oscillation phenomena in quantum wells.

Findings

Spin oscillations occur during spin diffusion.

Spin polarization can reverse direction.

Off-diagonal coherence is crucial for spin dynamics.

Abstract

By studying the time and spatial evolution of a pulse of the spin polarization in $n$-type semiconductor quantum wells, we highlight the importance of the off-diagonal spin coherence in spin diffusion and transport. Spin oscillations and spin polarization reverse along the the direction of spin diffusion in the absence of the applied magnetic field are predicted from our investigation.