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Title: Electron-phonon interaction in two dimensions: Variation of Im[Sigma]([epsilon][sub [ital p]],[omega]) with increasing [omega][sub [ital D]]/[ital E][sub [ital F]]

Journal Article · · Physical Review, B: Condensed Matter; (United States)
;  [1]
  1. Department of Physics, Brock University, St. Catharines, Ontario, L2S 3A1 (Canada)

The interaction between phonons and a two-dimensional (2D) electron gas is studied beyond the Migdal approximation. The analysis of the vertex function leads to the relative correction of [vert bar]Im[Sigma]([epsilon][sub [ital p]],[omega])[vert bar] which is of the order of [lambda]([Omega][sub ph]+[ital aT])[ital E][sub [ital F]][sup [minus]1]ln([ital E][sub [ital F]]/[Omega][sub ph]). Here, [Omega][sub ph] is the average phonon frequency, and [ital a]([similar to]1) is the ratio between coupling constants for low-frequency and high-frequency phonon modes. For [vert bar][omega][vert bar][much gt][Omega][sub ph] the correction is [vert bar][omega][vert bar]/[ital E][sub [ital F]]. The physically relevant result is that significant corrections are present only when [vert bar][omega][vert bar][approx lt][Omega][sub ph],[vert bar][omega][minus][epsilon][sub [ital p]][vert bar][approx lt][Omega][sub ph] and they increase with temperature as [ital T][sup [delta]] with [delta][le]1 in the entire frequency region. Also, our results strongly suggest that the quasiparticle picture for a 2D electron gas in a 3D lattice has to be corrected by many-particle effects even at small [omega][sub [ital D]]/[ital E][sub [ital F]].

OSTI ID:
5722815
Journal Information:
Physical Review, B: Condensed Matter; (United States), Vol. 48:22; ISSN 0163-1829
Country of Publication:
United States
Language:
English