# Short-scale quantum kinetic theory including spin-orbit interactions

## TL;DR

This paper develops a comprehensive quantum kinetic theory for spin-1/2 particles that incorporates spin-orbit interactions and particle dispersive effects, providing new insights into plasma wave behavior and damping mechanisms.

## Contribution

It introduces a gauge-invariant Wigner-based kinetic model including spin-orbit effects, with a novel term involving electric and magnetic fields, extending previous theories.

## Key findings

- Derived dispersion relations for electrostatic and electromagnetic waves.
- Compared Landau damping effects with and without spin-orbit interactions.
- Highlighted the role of hidden momentum in plasma dynamics.

## Abstract

We present a quantum kinetic theory for spin-$1/2$ particles, including the spin-orbit interaction, retaining particle dispersive effects to all orders in $\hbar$, based on a gauge-invariant Wigner transformation. Compared to previous works, the spin-orbit interaction leads to a new term in the kinetic equation, containing both the electric and magnetic fields. Like other models with spin-orbit interactions, our model features "hidden momentum". As an example application, we calculate the dispersion relation for linear electrostatic waves in a magnetized plasma, and electromagnetic waves in a unmagnetized plasma. In the former case, we compare the Landau damping due to spin-orbit interactions to that due to the free current. We also discuss our model in relation to previously published works.