Wave packet dynamics in 2DEG with spin orbit coupling: splitting and zitterbewegung

TL;DR

This paper investigates how spin orbit coupling affects wave packet dynamics in 2D electron gases, revealing splitting, zitterbewegung, and complex motion patterns influenced by magnetic fields and coupling strength.

Contribution

It provides a detailed analysis of wave packet splitting and zitterbewegung in 2DEG with Rashba spin orbit coupling, including effects of magnetic fields and different coupling regimes.

Findings

Wave packets split into spin-polarized parts with different velocities.

External magnetic fields cause wave packet splitting and rotation with distinct cyclotron frequencies.

Electron density distribution becomes irregular over time around cyclotron orbits.

Abstract

We study the effect of splitting and zitterbewegung of 1D and 2D electron wave packets in the semiconductor quantum well under the influence of the Rashba spin orbit coupling. Results of our investigations show that the spin orbit interaction induces dramatic qualitative changes in the evolution of spin polarized wave packet. The initial wave packet splits into two parts with different spin polarization propagating with unequal group velocity. This splitting appears due to the presence of two branches of electron spectrum corresponding to the stationary states with different chirality. It is demonstrated also that in the presence of external magnetic field B$ perpendicular to the electron gas plane the wave packet splits into two parts which rotates with different cyclotron frequencies. It was shown that after some periods the electron density distributes around cyclotron orbit and the motion acquire an irregular character. Our calculations were made for both cases of weak and strong spin orbit coupling.