Charge dynamics in the Mott insulating phase of the ionic Hubbard model

A. A. ALIGIA

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

APS

Año: 2004 vol. 69 p. 1 - 4

0163-1829

EL SISTEMA (ENGORROSO) PROPUESTO, NO PERMITE INGRESAR LAS PAGINAS DE ACUERDO A LA NUMERACION DEL PHYS.REV. B, ASI QUE LAS ESCRIBO AQUI, Y LO MISMO PARA LAS REFERENCIAS QUE SIGUEN PAGINAS 041101(R)-1 A041101(R)-4 I extend to charge and bond operators the transformation that maps the ionic Hubbard model at half filling onto an effective spin Hamiltonian. Using the transformed operators I calculate the amplitude of the charge density wave in different dimensions D. In one dimension, the charge-charge correlations at large distance d decay as d^(-3) ln^(-3/2)d, in spite of the finite charge gap, due to remaining charge-spin coupling. Bond-bond correlations decay as (-1)^d d^(-1) ln^(-3/2)d as in the usual Hubbard model