Abstract
We study the ground-state phase diagram of the Anderson-Hubbard model with correlated hopping at half-filling in one dimension. The Hamiltonian has a local Coulomb repulsion and a disorder potential with local energies randomly distributed in the interval with equal probability, acting on the singly occupied sites. The hopping process which modifies the number of doubly occupied sites is forbidden. The hopping between nearest-neighbor singly occupied and empty sites or between singly occupied and doubly occupied sites has the same amplitude . We identify three different phases as functions of the disorder amplitude and Coulomb interaction strength . When the system shows a metallic phase: (i) only when no disorder is present or an Anderson-localized phase, (ii) when disorder is introduced . When the Anderson-localized phase survives as long as disorder effects dominate on the interaction effects, otherwise a Mott-insulator phase (iii) arises. Phases (i) and (ii) are characterized by a finite density of doublons and a vanishing charge gap among the ground state and the excited states. Phase (iii) is characterized by the vanishing density of doublons and a finite gap for the charge excitations.
- Received 31 August 2016
- Revised 6 June 2017
DOI:https://doi.org/10.1103/PhysRevB.96.045413
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