Purely electronic terahertz polarization in dimer Mott insulators

2010/03/24 by Hiroki Gomi, Takayuki Imai, Akira Takahashi +1
Engineering · Materials Science · Physics and Astronomy · #Organic and Molecular Conductors Research #Perovskite Materials and Applications #Solid-state spectroscopy and crystallography #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.82.035101

5 pages, 5 figures, RevTeX4

arxiv created 2010/03/24 · openalex publication_date 2010/07/01 · arxiv updated 2015/05/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We theoretically describe purely electronic polarization modes in terahertz frequency region in dimer Mott insulators \ensuremathκ\text\ensuremath-(BEDT-TTF)₂X. The unusual low-frequency modes arise from the coupling between the oscillation of intradimer electric dipole moments and that of alternating interdimer bond orders. These collective modes play an important role in the dynamical dielectric properties of the dimer Mott insulators. Near the phase boundary of the dimer Mott transition, the ferroelectric ground state is realized by introducing electron-lattice coupling as a result of the softening of one of these collective modes.

Citations

• Spin and Charge Fluctuations and Lattice Effects on Charge Ordering in α-(BEDT-TTF)2I3
• Magnetodielectric phenomena in a charge- and spin-frustrated system of layered iron oxide
• Anomalous Lattice Response at the Mott Transition in a Quasi-2D Organic Conductor
• Finite-Temperature Phase Diagram of Quasi-One-Dimensional Molecular Conductors: Quantum Monte Carlo Study
• Spin Liquid State in an Organic Mott Insulator with a Triangular Lattice