Novel features of electromagnetic waves in an isotropic degenerate electron-ion plasma

Abstract

Within the framework of kinetic theory, the nonlinear interaction of electromagnetic waves (EMWs) with a degenerate electron-ion plasma is studied to account for the electron quantum mechanical effects. For this purpose, a specific quantum regime is considered, for which the degenerate electron Fermi velocity is assumed to be taken of the order of group velocity of EMWs. This eventually leads to the existence of nonlinear Landau damping rate for the EMWs in the presence of electron Ponderomotive force. The electrons-ion density oscillations may be arisen from the nonlinear interaction of EMWs, leading to a new type of nonlinear Schrödinger equation in terms of a complex amplitude for electromagnetic pump wave. The profiles of nonlinear damping rate reveal that EMWs become less damped for increasing the quantum tunnelling effects. The electrostatic response for the linear electrostatic waves is also investigated and derived a linear dispersion for the ion-acoustic damping rate. The latter is a direct function of electron Fermi speed and does not rely on the Bohm tunneling effect. The obtained results are numerically analyzed for the two microwaves of different harmonics in the context of nonrelativistic astrophysical dense plasma environments, e.g., white dwarfs, where the electron quantum corrections cannot be ignored.

Signatures of quantized magnetic field on the nonlinear Landau damping of transverse electromagnetic waves

“…Here x − dependent amplitude A 0 (x, t) is chosen as perpendicular to the direction of propagation of EM waves. Thus, we start with the Vlasov equations to describe the dynamics of fermions in the presence of Ponderomotive force, electric force, as well as the quantum force [51]:…”

“…f e1 (= f e0 ) is the perturbed (equilibrium) electron distribution function and f i1 (= f i0 ) represents the perturbed (equilibrium) ion distribution function. The angular brackets show the averaging over the slow space and temporal period of EM waves, while F ze is the Ponderomotive force that is experienced by the electrons only as defined in the nonrelativistic limit [51] as…”

“…One need to investigate the nonlinear coupling of waves and wave-particle interaction at quantum scales though some efforts have been carried out to study the LD of electrons and photons [48][49][50]. Shatadru and Roy [51] have examined the effect of relativistic electrons on the NLD and estimated the effective frequency shift and energy transfer rate. Debjani and Misra [52] have revisited the theory of NLD for electrostatic envelope solitons in quantum electron-positron plasmas and found a reduction in the LD rate and decay rate of solitary wave amplitude as compared to classical counterpart.…”

“…The EM waves with ultra-relativistic amplitude have also been studied [53] to identify a more effective damping of EM waves in an electron-positron-ion plasma. Recently, a modified NLD rate of the EM waves has been investigated [51] with quantum corrections including the Fermi statistics and Bohm potential.…”

“…In the present work, we aim to investigate the effect of a strong magnetic field, manifesting itself via the quantization of gyratory motion of fermions (electrons) [1] on the NLD of transverse EM waves and on the linear damping of longitudinal waves. Thus, the previous model [51] is revisited to study degenerate electron-ion plasma by taking into account a modified Fermi distribution for quantized fermi electron. The present model has interesting implications both in astrophysical objects like pulsars and magnetars, which are naturally confined with strong magnetic fields H  10 8 − 10 13 G [1], as well as in laboratory experiments where magnetic fields of the order of 10 7 G exist in n-Type GaAs semiconductors [52].We note that the LD in the bulk InSb semiconductor has also been studied [53] by using ultrashort laser pulses for coherent excitations of homogeneous electron-donor ion plasma, showing the loss of collective behavior at large propagation scale and LD accompanied by a blue-shift of the plasma frequency.…”