This article is cited in 23 papers

REVIEWS OF TOPICAL PROBLEMS

Pekar's ansatz and the strong coupling problem in polaron theory

V. D. Lakhno

Institute of Mathematical Problems of Biology, Russian Academy of Sciences, Pushchino, Moscow region

Abstract: The translationally invariant polaron theory of Tulub, which does not involve Pekar's ansatz (believed to provide an asymptotically exact solution in the strong-coupling limit) and fundamentally produces a lower-energy polaron than when using the ansatz, is discussed in detail. For the bipolaron, the theory yields the best values for bonding energy and for critical stability parameters. A variety of physical implications of the existence of translationally invariant polarons and bipolarons are discussed.

Keywords: Fröhlich Hamiltonian, Lee–Low–Pines transformation, weak coupling, Bose condensate, F-center.

PACS: 71.38.-k, 74.20.-z, 74.72.-h

Received: November 29, 2013
Revised: December 10, 2014
Accepted: May 20, 2014

DOI: 10.3367/UFNr.0185.201503d.0317

 English version: Physics–Uspekhi, 2015, 58:3, 295–308

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