Charge ordering and coexistence of charge fluctuations in quasi-two-dimensional organic conductors $\theta$-(BEDT-TTF)${}_{2}X$

Abstract

We present a scenario for the peculiar coexistence of charge fluctuations observed in quasi-2D 1/4-filled organic conductors $\theta$-(BEDT-TTF)${}_{2}X$ in the quantum critical regime where the charge ordering is suppressed down to zero temperature. The scenario is explored in the extended Hubbard model including electron-phonon couplings on an anisotropic triangular lattice. We find that the coexisting fluctuations emerge from two different instabilities, the ``Wigner crystallization on lattice'' driven by the off-site Coulomb repulsion and the charge-density-wave formation due to the nesting of the Fermi surface, not from phase competition or real-space inhomogeneity. This mechanism explains the contrastive temperature dependence of two fluctuations in experiments.

arXiv comment4 pages, 3 figures

References in corpus (9)

• Charge Ordering in Organic ET Compounds
• Strong coupling theory of the spinless charges on the triangular lattices: possibility of a new quantum liquid
• Large dielectric constant and giant nonlinear conduction in the organic conductor theta-(BEDT-TTF)_2CsZn(SCN)_4
• Quantum Melting of Charge Order due to Frustration in Two-Dimensional Quarter-Filled Systems
• Novel Charge Order and Superconductivity in Two-Dimensional Frustrated Lattice at Quarter Filling
• Charge ordering in theta-(BEDT-TTF)_2 X materials
• Mean-field study of charge order with long periodicity in $\theta$-(BEDT-TTF)${}_2$X
• The Origin of the Charge Ordering and Its Relevance to Superconductivity in $\theta$-(BEDT-TTF)${}_2$X: The Effect of the Fermi Surface Nesting and the Distant Electron-Electron Interactions
• Phase Diagram of Spinless Fermions on an Anisotropic Triangular Lattice at Half-filling

Cited by in corpus (20)

• Crystallization and vitrification of electrons in a glass-forming charge liquid
• Growth Dynamics of Photoinduced Domains in Two-Dimensional Charge-Ordered Conductors Depending on Stabilization Mechanisms
• Charge Order with Structural Distortion in Organic Conductors: Comparison between θ-(ET)2RbZn(SCN)4 and α-(ET)2I3
• Phase diagram of the triangular extended Hubbard model
• Coexistence of distinct charge fluctuations in $\theta$-(BEDT-TTF)${}_2$X
• Charge, Lattice, and Spin Dynamics in Photoinduced Phase Transitions from Charge-Order-Insulator to Metal in Quasi-Two-Dimensional Organic Conductors
• Quantum critical behavior of electrons at the edge of charge order
• Charge-order fluctuations and superconductivity in two-dimensional organic metals
• Geometrical frustration effects on charge-driven quantum phase transitions
• Theoretical Aspects of Charge Correlations in $\theta$-(BEDT-TTF)${}_{2}X$
• Variational Monte Carlo Study of a Spinless Fermion t-V Model on a Triangular Lattice: Formation of a Pinball Liquid
• Long-Period Charge Correlations in Charge-Frustrated Molecular theta-(BEDT-TTF)2X
• Collective excitation of a short-range charge ordering in $\theta$-$\mbox{(BEDT-TTF)}_2\mbox{CsZn(SCN)}_4$
• Superconductivity in the Three-Fold Charge-Ordered Metal of the Triangular-Lattice Extended Hubbard Model
• Multiorbital kinetic effects on charge ordering of frustrated electrons on the triangular lattice
• Magnetic Field Effect in One-Dimensional Charge Ordering Systems
• Thermal algebraic-decay charge liquid driven by competing short-range Coulomb repulsion
• Nonlinear Conduction by Melting of Stripe-Type Charge Order in Organic Conductors with Triangular Lattices
• Role of hydrogen bonding in charge-ordered organic conductor $\alpha$-(BEDT-TTF)${}_2$I${}_3$ probed by ${}^{127}$I nuclear quadrupole resonance
• Comparison of the charge-crystal and charge-glass state in geometrically frustrated organic conductors studied by fluctuation spectroscopy