The charge-density wave instability in quasi one-dimensional conductors

Abstract

Recent studies of the charge-density wave (CDW) instability in quasi one-dimensional conductors are reviewed. Relationships between the critical wave vector(s) of the CDW and the topology of the Fermi surface are emphasized. A method is given to extract the various response functions from x-ray diffuse scattering measurements in the case of non interacting electrons and on this basis, it is shown that the mechanism of the CDW instability differs markedly between the inorganic materials and the charge transfer salts of the TTF-TCNQ family. The dynamics of the CDW fluctuations above and below the Peierls transition are also analyzed from inelastic neutron scattering measurements performed on the blue bronzes. Finally the influence of defects, through the formation of Friedel oscillations, on the CDW instability is also considered.

Key Words:

• One-dimensional conductors
• charge density waves
• Peierls transition
• structural transitions