Disorder and pseudogap in strongly correlated systems: Phase diagram in the DMFT + {Sigma} approach

Journal Article · Sat Jun 15 04:00:00 EDT 2013 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776113060198· OSTI ID:22122849

The influence of disorder and pseudogap fluctuations on the Mott insulator-metal transition in strongly correlated systems has been studied in the framework of the generalized dynamic mean field theory (DMFT + {Sigma} approach). Using the results of investigations of the density of states (DOS) and optical conductivity, a phase diagram (disorder-Hubbard interaction-temperature) is constructed for the paramagnetic Anderson-Hubbard model, which allows both the effects of strong electron correlations and the influence of strong disorder to be considered. Strong correlations are described using the DMFT, while a strong disorder is described using a generalized self-consistent theory of localization. The DOS and optical conductivity of the paramagnetic Hubbard model have been studied in a pseudogap state caused by antiferromagnetic spin (or charge) short-range order fluctuations with a finite correlation length, which have been modeled by a static Gaussian random field. The effect of a pseudogap on the Mott insulator-metal transition has been studied. It is established that, in both cases, the static Gaussian random field (related to the disorder or pseudogap fluctuations) leads to suppression of the Mott transition, broadening of the coexistence region of the insulator and metal phases, and an increase in the critical temperature at which the coexistence region disappears.

• OSTI ID: 22122849
• Journal Information: Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 6 Vol. 116; ISSN JTPHES; ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTIFERROMAGNETISM
CRITICAL TEMPERATURE
DENSITY
ELECTRON CORRELATION
FLUCTUATIONS
GAUSS FUNCTION
HUBBARD MODEL
MEAN-FIELD THEORY
PARAMAGNETISM
PHASE DIAGRAMS
SPIN