### Abstract

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)_{2}I_{3}, 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)_{2}X, however, such a collective motion does not appear, and quantum phonons are hardly excited.

Original language | English |
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Pages (from-to) | 372-374 |

Number of pages | 3 |

Journal | Acta Physica Polonica A |

Volume | 121 |

Issue number | 2 |

DOIs | |

Publication status | Published - 2012 Jan 1 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Acta Physica Polonica A*,

*121*(2), 372-374. https://doi.org/10.12693/APhysPolA.121.372