Electron Correlations and Spatial Configuration of the Bipolaron

✍ Scribed by N.I. Kashirina; V.D. Lakhno; V.V. Sychyov

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 101 KB
• Volume: 234
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/1521-3951(200211)234:2<563::aid-pssb563>3.0.co;2-e

✦ Synopsis

Bipolaron energy is calculated for various distances between the centers of polarization wells of two polarons with accounting the electron correlations. A singlet bipolaron is stable at a rather high energy of ion binding h h m % 0:143, h ¼ e 1 =e 0 (e 1 and e 0 are the high-frequency and static dielectric constants, respectively). The unique energy minimum corresponds to a one-center bipolaron (analog of a helium atom). The bipolaron binding energy constitutes up to 25.8 % of a double polaron energy at h ! 0. A triplet bipolaron (analog of ortho-helium) is energetically disadvantageous. The one-center configuration of a triplet bipolaron corresponds to a maximum on the distance dependence of the total energy J Bp ðRÞ. The exchange interaction between polarons has antiferromagnetic character. A prediction is made about a possibility of Wigner crystallization of a polaron gas, which occurs with antiferromagnetic ordering in the polaron system.