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Band effects on the conductivity for a two-band Hubbard model |
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| Authors: | S-J Gu J Cao S Chen Y Liu H-Q Lin |
| Institution: | (1) Department of Physics and Institute of Theoretical Physics, The Chinese University of Hong Kong, Hong Kong, P.R. China;(2) Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P.R. China |
| Abstract: | The band effects on the conductivity of a one-dimensional two-band Hubbard model is studied based on the ground state energy analysis. It is found that the system with filling factor one is a metal at zero temperature if the on-site interaction U is smaller than a critical value Uc, and is an insulator if U is larger than Uc. The value of metal-insulator transition point Uc is obtained. This result is different from that of 1D single-band Hubbard model where the quantum phase transition point Uc=0. Therefore, the orbital degree of freedom plays an essential role in the states of matter. |
| Keywords: | PACS" target="_blank">PACS 71 30 +h Metal-insulator transitions and other electronic transitions 71 10 Fd Lattice fermion models (Hubbard model etc ) 74 70 -b Superconducting materials |
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