TY - JOUR

T1 - Interplay between correlated electrons and quantum phonons in charge-ordered and Mott-insulating organic compounds

AU - Yonemitsu, K.

AU - Maeshima, N.

AU - Tanaka, Y.

PY - 2012/2

Y1 - 2012/2

N2 - At an early stage of the photoinduced transition from an insulator to a metal in quasi-two-dimensional organic conductors, a coherent motion of electrons is observed in a charge-ordered insulator, but not so far in a Mott insulator. The mechanisms of these different photoinduced charge dynamics are theoretically studied by numerical solutions to the time-dependent Schrödinger equation for exact many-electron-phonon wave functions on small clusters of model systems. We use two-dimensional three-quarter-filled extended Holstein-Hubbard models on anisotropic triangular lattices. For a charge-ordered insulator on a lattice simplified from the structure of α-(BEDT-TTF)2I3, we indeed find a low-energy collective electronic motion coupled with quantum phonons even if the energy of photoexcitation is away from this energy. For a Mott insulator on a lattice simplified from the structure of κ-(BEDT-TTF)2X, however, such a collective motion does not appear, and quantum phonons are hardly excited.

AB - At an early stage of the photoinduced transition from an insulator to a metal in quasi-two-dimensional organic conductors, a coherent motion of electrons is observed in a charge-ordered insulator, but not so far in a Mott insulator. The mechanisms of these different photoinduced charge dynamics are theoretically studied by numerical solutions to the time-dependent Schrödinger equation for exact many-electron-phonon wave functions on small clusters of model systems. We use two-dimensional three-quarter-filled extended Holstein-Hubbard models on anisotropic triangular lattices. For a charge-ordered insulator on a lattice simplified from the structure of α-(BEDT-TTF)2I3, we indeed find a low-energy collective electronic motion coupled with quantum phonons even if the energy of photoexcitation is away from this energy. For a Mott insulator on a lattice simplified from the structure of κ-(BEDT-TTF)2X, however, such a collective motion does not appear, and quantum phonons are hardly excited.

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U2 - 10.12693/APhysPolA.121.372

DO - 10.12693/APhysPolA.121.372

M3 - Article

AN - SCOPUS:84863408219

SN - 0587-4246

VL - 121

SP - 372

EP - 374

JO - Acta Physica Polonica A

JF - Acta Physica Polonica A

IS - 2

ER -