Theoretical Studies on Phase Transitions in Quasi-One-Dimensional Molecular Conductors

Abstract

A review is given for recent theoretical studies on phase transitions in quasi-one-dimensional molecular conductors with a quarter-filled band. By lowering temperature, charge transfer salts exhibit a variety of transitions accompanying symmetry breaking, such as charge ordering, lattice dimerization, antiferromagnetic transition, spin-Peierls distortion, and so on. Analyses on microscopic quasi-one-dimensional models provide their systematic understandings, by the complementary use of different analytical and numerical techniques; they can reproduce finite-temperature phase transitions, whose results can be directly compared with experiments and give feedbacks to material design.

Keywords

• molecular conductors
• quasi-one-dimension
• phase transition
• charge order
• metal-insulator transition
• symmetry breaking
• bosonization
• renormalization group
• quantum Monte Carlo
• extended Hubbard model