Multimode Pseudo Jahn-Teller Effect for Off-Centre Impurities in Crystals

✍ Scribed by G. I. Bersuker; V. Z. Polinger

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 490 KB
• Volume: 125
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2221250147

✦ Synopsis

Abstract

Systems with off‐centre impurity in the orbitally nondegenerate ground state are discussed. The off‐centre position of the impurity is shown to result from the mixing of the ground state and one of the excited electronic states by odd crystalline vibrations, displacing the impurity from the lattice point (pseudo Jahn‐Teller effect, PJTE). At high enough temperatures transitions of the impurity between the equivalent off‐centre positions occur due to the coupling with the PJTE active phonons. The qualitative estimation of the transition probability obtained for this process is in agreement with the line broadening data for the Li^+^ :KCl.