Wavepacket dynamics in one-dimensional extended Hubbard model

一次元拡張ハバード模型における波束ダイナミクス

大西 弘明  ; Dagotto, E.*

Onishi, Hiroaki; Dagotto, E.*

We study transport properties of a one-dimensional extended Hubbard model with the intra-site and the inter-site Coulomb interactions at half filling, analyzing the time evolution of wavepackets by a time-dependent DMRG method. When 0 and =0, the charge wavepacket cannot transmit into the Mott insulator due to a charge gap, while a part of the spin wavepacket enters the Mott insulator, since there is no spin gap. Thus we observe the spin injection in the metal/Mott-insulator junction. On the other hand, the charge/spin wavepackets in the 0 case show exactly the same behavior of the spin/charge wavepackets in the 0 case due to the conversion of spin and charge degrees of freedom via the particle-hole transformation. When we introduce 0 in addition to 0, we clearly observe that the charge wavepacket exhibits a negative reflection, indicating the Andreev reflection in the metal/superconductor junction.