Plasmons carrying orbital angular momentum in a partially degenerate plasma
摘要
This paper examines how quantum electron plasma waves (EPWs) can carry orbital angular momentum (OAM) when a Laguerre-Gaussian (LG) laser beam interacts with a specialized type of plasma. This plasma consists of inertial electrons (neither fully classical nor fully degenerate but instead existing in an intermediate degenerate state) and non-degenerate stationary ions. Such a state reflects the realistic conditions of laboratory plasmas, particularly those found in inertial confinement fusion (ICF) experiments. Unlike the idealized extreme of very high and very low temperatures, this intermediate regime is both physically meaningful and experimentally achievable, making it especially relevant for practical applications. By applying the quantum hydrodynamic model and working within the paraxial approximation, we derive a dispersion relation that governs how these OAM-carrying plasmons behave. Our analysis reveals that electric field lines form a helical pattern, characterized by a strong central (axial) component, which is a key signature of angular momentum transfer. We also examine how the structure of the laser beam, particularly its radial and angular mode numbers, affects electrostatic potential and field distribution within the plasma. These findings deepen our understanding of light-plasma interaction in quantum regimes and point towards new ways to manipulate and study plasmas in a real-world experimental setup.