Anderson-Mott transition in a disordered Hubbard chain with correlated hopping

LILIANA ARRACHEA ; FRANCESCA BATTISTA; ALBERTO CAMJAYI

Physical Review B

American Physical Society

Año: 2017 vol. 96 p. 45413 - 45413

2469-9950

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 U and a disorder potential with local energies randomly distributed in the interval (−W,+W) 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 have the same amplitude t. We identify three different phases as functions of the disorder amplitude W and Coulomb interaction strength U>0. When U4t the Anderson-localized phase survives as long as disorder effects dominates on the interaction effects, otherwise a Mott insulator phase (iii) arises. The phases (i) and (ii) are characterized by a finite density of doublons and a vanishing charge gap between the ground state and the excited states. The phase (iii) is characterized by vanishing density of doublons and a finite gap for the charge excitations.