Finite Temperature Properties of Geometrically Charge Frustrated Systems

Abstract

We theoretically study finite temperature properties of interacting fermion systems under geometrical frustration in the charge degree of freedom. Physical quantities such as charge structure factors, the specific heat, and the entropy, of the two-dimensional model of interacting spinless fermions on an anisotropic triangular lattice are numerically calculated using the thermal pure quantum state. By considering the Coulomb interactions up to the next-nearest-neighbor bonds, we elucidate that in the highly frustrated region where a long-period stripe-type charge order (CO) is the ground state, fluctuations of different stripe-type CO patterns become large at finite temperatures. When we further introduce $1/r$-type long-range Coulomb interactions, the ground state unexpectedly recovers the non-stripe-type 3-fold CO pattern characteristic of triangular lattice models with short-range interactions. Our results imply that the BEDT-TTF-based organic conductors exhibiting glass-like behavior locates in the region of the intermediate strength of long-range interactions, where both the stripe- and non-stripe-type CO fluctuations are prominent.

6 pages, 4 figures

References in corpus (11)

• Theoretical Aspects of Charge Ordering in Molecular Conductors
• Quantum Lattice Model Solver $\mathcal{H}\Phi$
• 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
• Novel Charge Order and Superconductivity in Two-Dimensional Frustrated Lattice at Quarter Filling
• Crystallization and vitrification of electrons in a glass-forming charge liquid
• Emergence of non-equilibrium charge dynamics in a charge-cluster glass
• Coexistence of distinct charge fluctuations in $\theta$-(BEDT-TTF)${}_2$X
• Systematic Variations in the Charge-Glass-Forming Ability of Geometrically Frustrated $\theta$-(BEDT-TTF)${}_{2}X$ Organic Conductors
• Unconventional metallic conduction in two-dimensional Hubbard-Wigner lattices
• Charge Dynamics in a Correlated Fermion System on a Geometrically Frustrated Lattice

Cited by in corpus (3)

• Interaction-induced quantum spin Hall insulator in the organic Dirac electron system $\alpha$-(BEDT-TSeF)${}_2$I${}_3$
• Anomalous 2D-confined electronic transport in layered organic charge-glass systems
• Ferrimagnetism Induced by Off-Site Coulomb Interaction in an Itinerant Electron System