|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Peer-reviewed Journal Articles, etc >
Frustrated Electron Liquids in the Hubbard Model
| Title: | Frustrated Electron Liquids in the Hubbard Model |
| Authors: | Ohkawa, Fusayoshi J. Browse this author →KAKEN DB | | Toyama, Takahiro Browse this author |
| Keywords: | Mott insulator | | metal-insulator transition | | Hubbard model | | single-site approximation | | Kondo effect | | Kondo lattice | | Fermi liquid | | RVB | | frustration | | third law of thermodynamics |
| Issue Date: | Dec-2009 |
| Publisher: | Physical Society of Japan |
| Journal Title: | Journal of the Physical Society of Japan |
| Volume: | 78 |
| Issue: | 12 |
| Start Page: | 124707 |
| Publisher DOI: | 10.1143/JPSJ.78.124707 |
| Abstract: | The ground state of the Hubbard model is studied within the constrained Hilbert space where no order parameter exists. The self-energy of electrons is decomposed into the single-site and multisite self-energies. The calculation of the single-site self-energy is mapped to a problem of self-consistently determining and solving the Anderson model. When an electron reservoir is explicitly considered, it is proved that the single-site self-energy is that of a normal Fermi liquid even if the multisite self-energy is anomalous. Thus, the ground state is a normal Fermi liquid in the supreme single-site approximation (S3A). In the strong-coupling regime, the Fermi liquid is stabilized by the Kondo effect in the S3A and is further stabilized by the Fock-type term of the superexchange interaction or the resonating-valence-bond (RVB) mechanism beyond the S3A. The stabilized Fermi liquid is frustrated as much as an RVB spin liquid in the Heisenberg model. It is a relevant unperturbed state that can be used to study a normal or anomalous Fermi liquid and an ordered state in the whole Hilbert space by Kondo lattice theory. Even if higher-order multisite terms than the Fock-type term are considered, the ground state cannot be a Mott insulator. It can be merely a gapless semiconductor even if the multisite self-energy is so anomalous that it is divergent at the chemical potential. A Mott insulator is only possible as a high temperature phase. |
| Rights: | © 2009 The Physical Society of Japan |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/40076 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 大川 房義
|
