Premium
Second Order Conductivity and Nonlinear Plasma Excitation of an Isotropic Electron Gas
Author(s) -
Stolz H.
Publication year - 1967
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19670210105
Subject(s) - physics , electron , plasma , isotropy , excitation , conductivity , tensor (intrinsic definition) , harmonics , anisotropy , plasma oscillation , quantum electrodynamics , condensed matter physics , atomic physics , quantum mechanics , mathematics , voltage , pure mathematics
The theory of the second order conductivity tensor of an isotropic electron gas is developed using thermodynamic Green's functions. It is shown that this quantity is exactly determined by the first order conductivity tensor and an additional term consisting of a pure three‐current correlation function. This term is found to be small in the optical and plasma regions. The second order conductivity tensor is calculated in the Hartree approximation. The poles of the second order response function relating the induced particle density to a scalar external potential are discussed and shown to yield the second and zeroth harmonics of the ordinary plasma waves as determined by the linear response of the system. For the special case of shock excitation by a Coulomb potential, semiquantitative arguments are presented in favour of a non‐negligible second order contribution to the total density response which may possibly also contribute to the energy loss of fast electrons in metals.