Nonlinear Conduction by Melting of Stripe-Type Charge Order in Organic Conductors with Triangular Lattices

Abstract

We theoretically discuss the mechanism for the peculiar nonlinear conduction in quasi-two-dimensional organic conductors θ-(BEDT-TTF)2X [BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene] through the melting of stripe-type charge order. An extended Peierls-Hubbard model attached to metallic electrodes is investigated by a nonequilibrium Green's function technique. A novel current-voltage characteristic appears in a coexistent state of stripe-type and nonstripe 3-fold charge orders, where the applied bias melts mainly the stripe-type charge order through the reduction of lattice distortion, whereas the 3-fold charge order survives. These contrastive responses of the two different charge orders are consistent with the experimental observations.

5 pages, 4 figures, to appear in J. Phys. Soc. Jpn

References in corpus (6)

• Theoretical Aspects of Charge Ordering in Molecular Conductors
• Charge ordering and coexistence of charge fluctuations in quasi-two-dimensional organic conductors $\theta$-(BEDT-TTF)${}_{2}X$
• Charge ordering in θ-(BEDT-TTF)2RbZn(SCN)4: Cooperative effects of electron correlations and lattice distortions
• Effects of Electron-Lattice Coupling on Charge Order in θ-(ET)2X
• Crossover from bias-induced to field-induced breakdowns in one-dimensional band and Mott insulators attached to electrodes
• Nonequilibrium Green's-Function Approach to the Suppression of Rectification at Metal--Mott-Insulator Interfaces

Cited by in corpus (1)

• Roles of Potential Gradient and Electrode Bandwidth on Negative Differential Resistance in One-Dimensional Band Insulator