Abstract
We investigate the properties of a two-orbital Hubbard model with unequal bandwidths on the square lattice in the framework of the dynamical cluster approximation (DCA) combined with a continuous-time quantum Monte Carlo algorithm. We explore the effect of short-range spatial fluctuations on the nature of the metal-insulator transition and the possible occurrence of an orbital-selective Mott transition (OSMT) as a function of cluster size Nc. We observe that for Nc=2 no OSMT is present, instead a band insulator state for both orbitals is stabilized at low temperatures due to the appearance of an artificial local ordered state. For Nc=4 the DCA calculations suggest the presence of five different phases which originate out of the cooperation and competition between spatial fluctuations and orbitals of different bandwidths and an OSMT phase is stabilized. Based on our results, we discuss the nature of the gap opening.
| Original language | English |
|---|---|
| Article number | 026402 |
| Journal | Physical Review Letters |
| Volume | 104 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Jan 15 2010 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
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Dynamical cluster approximation study of the anisotropic two-orbital hubbard model. / Lee, Hunpyo; Zhang, Yu Zhong; Jeschke, Harald Olaf; Valentí, Roser; Monien, Hartmut.
In: Physical Review Letters, Vol. 104, No. 2, 026402, 15.01.2010.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Dynamical cluster approximation study of the anisotropic two-orbital hubbard model
AU - Lee, Hunpyo
AU - Zhang, Yu Zhong
AU - Jeschke, Harald Olaf
AU - Valentí, Roser
AU - Monien, Hartmut
PY - 2010/1/15
Y1 - 2010/1/15
N2 - We investigate the properties of a two-orbital Hubbard model with unequal bandwidths on the square lattice in the framework of the dynamical cluster approximation (DCA) combined with a continuous-time quantum Monte Carlo algorithm. We explore the effect of short-range spatial fluctuations on the nature of the metal-insulator transition and the possible occurrence of an orbital-selective Mott transition (OSMT) as a function of cluster size Nc. We observe that for Nc=2 no OSMT is present, instead a band insulator state for both orbitals is stabilized at low temperatures due to the appearance of an artificial local ordered state. For Nc=4 the DCA calculations suggest the presence of five different phases which originate out of the cooperation and competition between spatial fluctuations and orbitals of different bandwidths and an OSMT phase is stabilized. Based on our results, we discuss the nature of the gap opening.
AB - We investigate the properties of a two-orbital Hubbard model with unequal bandwidths on the square lattice in the framework of the dynamical cluster approximation (DCA) combined with a continuous-time quantum Monte Carlo algorithm. We explore the effect of short-range spatial fluctuations on the nature of the metal-insulator transition and the possible occurrence of an orbital-selective Mott transition (OSMT) as a function of cluster size Nc. We observe that for Nc=2 no OSMT is present, instead a band insulator state for both orbitals is stabilized at low temperatures due to the appearance of an artificial local ordered state. For Nc=4 the DCA calculations suggest the presence of five different phases which originate out of the cooperation and competition between spatial fluctuations and orbitals of different bandwidths and an OSMT phase is stabilized. Based on our results, we discuss the nature of the gap opening.
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U2 - 10.1103/PhysRevLett.104.026402
DO - 10.1103/PhysRevLett.104.026402
M3 - Article
AN - SCOPUS:74549203447
VL - 104
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 2
M1 - 026402
ER -