Premium
Quantum Correction to the Classical Plasma Frequency in the Long‐Wavelength Limit
Author(s) -
Pal R. K.,
Tripathy D. N.,
Mandal S. S.
Publication year - 1980
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.2221000232
Subject(s) - random phase approximation , plasmon , long wavelength limit , degenerate energy levels , physics , plasma oscillation , wavelength , limit (mathematics) , plasma , dielectric function , quantum , dielectric , momentum (technical analysis) , local field , quantum electrodynamics , wave vector , atomic physics , condensed matter physics , field (mathematics) , quantum mechanics , mathematical analysis , mathematics , finance , pure mathematics , economics
A negative frequency shift is observed to the classical plasma frequency ω pl in metals in the long‐wavelength limit ( k = 0) by analysing the zeroes of the dielectric function of a degenerate many‐electron system evaluated beyond the random phase approximation (RPA). This is achieved by accounting for the non‐RPA contributions arising from the virtual plasmon effects of the effective interaction lines associated with the local field correction diagrams. Redefining the critical wave vector k c the experimentally observed frequency shift to ω pl is reproduced at k = 0 in Li, Al, and Na metals. The theory clearly indicates an extension of the plasmon modes to a momentum transfer region beyond k RPA c .