Experimental and theoretical research on nonadiabatic effects in metals is briefly reviewed. It is shown that these effects are most manifest in optical phonon spectra at small wave vectors q satisfying the condition qv_F < ω₀(q), where v_F is the electron Fermi velocity, and ω₀(q) is the phonon frequency. Various theoretical approaches to calculating nonadiabatic effects are examined. Fröhlich’s phenomenological field-theoretical model, the most widely used in such calculations, is discussed in detail, some aspects of its application are considered, and its efficiency as a tool for studying nonadiabatic effects is demonstrated.

PACS: 71.15.Mb, 74.20.−z, 74.72.−h (all) DOI: 10.1070/PU2008v051n06ABEH006462 URL: https://ufn.ru/en/articles/2008/6/a/ 000260064600001 2-s2.0-53849110876 2008PhyU...51..535M Citation: Maksimov E G, Karakozov A E "On nonadiabatic effects in phonon spectra of metals" Phys. Usp. 51 535–549 (2008) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Оригинал: Максимов Е Г, Каракозов А Е «О неадиабатических эффектах в фононных спектрах металлов» УФН 178 561–576 (2008); DOI: 10.3367/UFNr.0178.200806a.0561