2023/09/13 by Mikhail V. Medvedev, Medvedev, Mikhail V. · 1 citation
Physics and Astronomy · #Dust and Plasma Wave Phenomena #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.2309.07316
openalex publication_date 2023/09/13 · openalex created_date 2023/09/16 · openalex updated_date 2026/07/28
Ultra-magnetized plasmas, where the magnetic field strength exceeds the Schwinger field of about BQ≈4×1013~gauss, become of great scientific interest, thanks to the current advances in laser-plasma experiments and astrophysical observations of magnetar emission. These advances demand better understanding of how quantum electrodynamics (QED) effects influence collective plasma phenomena. In particular, Maxwell's equations become nonlinear in the strong-QED regime. Here we present the `QED plasma framework' which will allow one to \em systematically explore collective phenomena in a QED-plasma with arbitrarily strong magnetic field. Further, we illustrate the framework by exploring low-frequency modes in the ultra-magnetized, cold, electron-positron plasmas. We demonstrate that the classical picture of five branches holds in the QED regime; no new eigenmodes appear. The dispersion curves of all the modes are modified. The QED effects include the overall modification to the plasma frequency, which becomes field-dependent. They also modify resonances and cutoffs of the modes, which become both field- and angle-dependent. The strongest effects are (i) the \em field-induced transparency of plasma for the O-mode via the dramatic reduction of the low-frequency cutoff well below the plasma frequency, (ii) the \em Alfven mode suppression in the large-k regime via the reduction of the Alfven mode resonance, and (iii) the \em O-mode slowdown via strong angle-dependent increase of the index of refraction. These results should be important for understanding of a magnetospheric pair plasma of a magnetar and for laboratory laser-plasma experiments in the QED regime.