On the Strong Coupling Techniques of Polaron Theory

J. T. Devreese, R. P. Evrard

Research outputpeer-review

Abstract

The validity of Pekar's polaron theory is investigated by using it to solve Gross's simplified model in which the electron interacts with only one lattice oscillator. The results are compared with the exact solutions. This shows as expected, that Pekar's approximation provides an accurate strong coupling limit. The accuracy decreases with the mean number of virtual phonons, which is used to define the coupling strength. For a certain value of this parameter, Pekar's method becomes less accurate than the Lee‐Low‐Pines method. At this point the relative error is about 15%. The present study makes it possible to introduce an “intermediate coupling region” in Gross's model. In this region the relative error of the Lee‐Low‐Pines approximation is about 10%.

Original languageEnglish
Pages (from-to)403-410
Number of pages8
JournalPhysica Status Solidi (B)
Volume9
Issue number2
DOIs
StatePublished - 1965
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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