Quantum calculation of the Vavilov-Cherenkov radiation by twisted electrons

TL;DR

This paper provides a quantum electrodynamical analysis of Vavilov-Cherenkov radiation emitted by relativistic twisted electrons, revealing unique angular, polarization, and azimuthal asymmetry features that can serve as diagnostic tools.

Contribution

It introduces a detailed quantum description of Cherenkov radiation from twisted electrons, highlighting novel angular and polarization characteristics not seen in plane-wave cases.

Findings

Radiation occurs within an annular angular region with boundary enhancement.

Photons can have linear polarization in multiple directions.

Strong azimuthal asymmetry in radiation from superposed vortex states.

Abstract

We present the detailed quantum electrodynamical description of Vavilov-Cherenkov radiation emitted by a relativistic twisted electron in the transparent medium. Simple expressions for the spectral and spectral-angular distributions as well as for the polarization properties of the emitted radiation are obtained. Unlike the plane-wave case, the twisted electron produces radiation within the annular angular region, with enhancement towards its boundaries. Additionally, the emitted photons can have linear polarization not only in the scattering plane but also in the orthogonal direction. We find that the Vavilov-Cherenkov radiation emitted by an electron in a superposition of two vortex states exhibits a strong azimuthal asymmetry. Thus, the Vavilov-Cherenkov radiation offers itself as a convenient diagnostic tool of such electrons and complements the traditional microscopic imaging.