Role of Interchain Hopping in the Magnetic Susceptibility of Quasi-One-Dimensional Electron Systems(Condensed matter: electronic structure and electrical, magnetic, and optical properties)

概要

論文の詳細を見る
A role of interchain hopping in quasi-one-dimensional (Q-1D) electron systems is investigated by extending the Kadanoff-Wilson renormalization group of one-dimensional (1D) systems to Q-1D systems. This scheme is applied to the extended Hubbard model to calculate the temperature (T) dependence of the magnetic susceptibility, _X(T). The calculation is performed by taking into account not only the logarithmic Cooper and Peierls channels, but also the non-logarithmic Landau and finite momentum Cooper channels, which give relevant contributions to the uniform response at finite temperatures. It is shown that the interchain hopping, t_⊥, reduces _X(T) at low temperatures, while it enhances _X(T) at high temperatures. This notable t_⊥ dependence is ascribed to the fact that t_⊥ enhances the antiferromagnetic spin fluctuation at low temperatures, while it suppresses the 1D fluctuation at high temperatures. The result is at variance with the random-phase-approximation approach, which predicts an enhancement of _X(T) by t_⊥ over the whole temperature range. The influence of both the long-range repulsion and the nesting deviations on _X(T) is further investigated. We discuss the present results in connection with the data of _X(T) in the (TMTTF)_2X and (TMTSF)_2X series of Q-1D organic conductors, and propose a theoretical prediction for the effect of pressure on magnetic susceptibility.
社団法人日本物理学会の論文
2007-01-15