With the advent of high-temperature superconductors, research on polarons and bipolarons has gained renewed attention. It appears that carriers in some high-temperature superconductors are strongly correlated both in the normal and in the superconducting state. In the strong-coupling limit the Fermi-liquid ground state may be destroyed by the formation of small polarons and bipolarons. Experimental and theoretical analysis of such particles is a central issue for current research in superconductivity.

This book contains a series of authoritative articles on the most advanced research on polarons and bipolarons. They were invited for presentation during a workshop on ‘Polarons and Bipolarons in High-Tc Superconductors and Related Materials’, which was held at the Interdisciplinary Research Centre (IRC) in Superconductivity, Cambridge, UK, between 7th and 9th April 1994. Over 50 participants from ten countries took part in this workshop, representing the major research centres currently working in this field. The workshop was held in honour of Sir Nevill Mott in recognition of his important contributions to the physics of polarons.

The editors are grateful to all contributors for their overwhelmingly positive response to the idea of publishing this book. We are indebted to Ken Diffey and Margaret Hilton who ensured the smooth running of the workshop, to all of the referees and to William Beere for their help editing the manuscripts. We also thank Simon Capelin of Cambridge University Press for his encouragement and help throughout the publication of this book.