Semiclassical Dynamics of Electron Wave Packet States with Phase Vortices

TL;DR

This paper explores semiclassical electron wave packets with phase vortices carrying orbital angular momentum, revealing their unique dynamics, Berry curvature effects, and the OAM Hall effect in electric and magnetic fields.

Contribution

It introduces higher-order wave packet solutions with phase vortices and analyzes their semiclassical evolution, highlighting novel spin-orbit interactions and transverse forces.

Findings

Wave packets carry well-defined orbital angular momentum.

Berry curvature induces spin-orbit-like interactions.

OAM Hall effect observed in electron dynamics.

Abstract

We consider semiclassical higher-order wave packet solutions of the Schrodinger equation with phase vortices. The vortex line is aligned with the propagation direction, and the wave packet carries a well-defined orbital angular momentum (OAM) $\hbar l$ ($l$ is the vortex strength) along its main linear momentum. The probability current coils around momentum in such OAM states of electrons. In an electric field, these states evolve like massless particles with spin $l$. The magnetic-monopole Berry curvature appears in momentum space, which results in a spin-orbit-type interaction and a Berry/Magnus transverse force acting on the wave packet. This brings about the OAM Hall effect. In a magnetic field, there is a Zeeman interaction, which, can lead to more complicated dynamics.