Phase competitions and coexistences in quasi-one-dimensional molecular conductors: exact diagonalization study
نویسندگان
چکیده
We investigate ground state properties of a quasi-one-dimensional electron-lattice coupled model for quarter-filled molecular conductors. The effective one-dimensional extended Hubbard model coupled to adiabatic lattice degree of freedom is derived by the inter-chain mean-field approximation and solved by Lanczos exact diagonalization method. We find that the critical behavior among lattice tetramerized states with different charge-lattice ordered patterns is sensitively affected by the inter-chain Coulomb interaction, lattice anharmonicity, and intrinsic dimerization. This indicates a subtle balance between these states originating from strong correlation and reduced dimensionality.
منابع مشابه
Theoretical Studies on Phase Transitions in Quasi-One-Dimensional Molecular Conductors
A review is given for recent theoretical studies on phase transitions in quasi-one-dimensional molecular conductors with a quarter-filled band. By lowering temperature, charge transfer salts exhibit a variety of transitions accompanying symmetry breaking, such as charge ordering, lattice dimerization, antiferromagnetic transition, spin-Peierls distortion, and so on. Analyses on microscopic quas...
متن کاملAn exact-diagonalization study of rare events in disordered conductors
We determine the statistical properties of wave functions in disordered quantum systems by exact diagonalization of one-, twoand quasi-one dimensional tight-binding Hamiltonians. In the quasi-one dimensional case we find that the tails of the distribution of wave-function amplitudes are described by the non-linear σ-model. In two dimensions, the tails of the distribution function are consistent...
متن کاملTuning the magnetic dimensionality by charge ordering in the molecular TMTTF salts.
We theoretically investigate the interplay between charge ordering and magnetic states in quasi-one-dimensional molecular conductors TMTTF(2)X, motivated by the observation of a complex variation of competing and/or coexisting phases. We show that the ferroelectric-type charge order increases two-dimensional antiferromagnetic spin correlation, whereas in the one-dimensional regime two different...
متن کاملExact diagonalization study of the two-dimensional t-J-Holstein model.
Exact diagonalization study of the two-dimensional t − J−Holstein model (Received today) We study by exact diagonalization the two-dimensional t − J−Holstein model near quarter filling by retaining only few phonon modes in momentum space. This truncation allows us to incorporate the full dynamics of the retained phonon modes. The behavior of the kinetic energy, the charge structure factor and o...
متن کاملSuperconductivity and Antiferromagnetism in Quasi-one-dimensional Organic Conductors
We review the current understanding of superconductivity in the quasi-onedimensional organic conductors of the Bechgaard and Fabre salt families. We discuss the interplay between superconductivity, antiferromagnetism, and charge-density-wave fluctuations. The connection to recent experimental observations supporting unconventional pairing and the possibility of a tripletspin order parameter for...
متن کامل