Coexistence of distinct charge fluctuations in $\theta$-(BEDT-TTF)${}_2$X

Abstract

Using the Lanczos exact-diagonalization and density-matrix renormalization group methods, we study the extended Hubbard model at quarter filling defined on the anisotropic triangular lattice. We focus on charge ordering (CO) phenomena induced by onsite and intersite Coulomb interactions. We determine the ground-state phase diagram including three CO phases, i.e., diagonal, vertical, and three-fold CO phases, based on the calculated results of the hole density and double occupancy. We also calculate the dynamical density-density correlation functions and find possible coexistence of the diagonal and three-fold charge fluctuations in a certain parameter region where the onsite and intersite interactions compete. Furthermore, the characteristic features of the optical conductivity for each CO phase are discussed.

9 pages, 7 figures

References in corpus (8)

• Strong coupling theory of the spinless charges on the triangular lattices: possibility of a new quantum liquid
• Quantum Melting of Charge Order due to Frustration in Two-Dimensional Quarter-Filled Systems
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• 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
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Cited by in corpus (3)

• Variational Monte Carlo Study of a Spinless Fermion t-V Model on a Triangular Lattice: Formation of a Pinball Liquid
• Photo-Induced Dynamics in Charge-Frustrated Systems
• Charge Dynamics in a Correlated Fermion System on a Geometrically Frustrated Lattice