Strong-coupling expansions for the topologically inhomogeneous Bose-Hubbard model
Year: 2004
Authors: Buonsante P., Penna V., Vezzani A.
Autors Affiliation: Dipartimento di Fisica and INFM – Politecnico di Torino
Dipartimento di Fisica and INFM – Università degli Studi di Parma
Abstract: We consider a Bose-Hubbard model with an arbitrary hopping term and provide the boundary of the insulating phase thereof in terms of third-order strong coupling perturbative expansions for the ground state energy. In the general case two previously unreported terms occur, arising from triangular loops and hopping inhomogeneities, respectively. Quite interestingly the latter involves the entire spectrum of the hopping matrix rather than its maximal eigenpair, like the remaining perturbative terms. We also show that hopping inhomogeneities produce a first order correction in the local density of bosons. Our results apply to ultracold bosons trapped in confining potentials with arbitrary topology, including the realistic case of optical superlattices with uneven hopping amplitudes. Significant examples are provided. Furthermore, our results can be extented to magnetically tuned transitions in Josephson junction arrays.
Journal/Review: PHYSICAL REVIEW B
Volume: 70 (18) Pages from: 184520 to: 184520
KeyWords: lattice bosons; quantum phase transitions; strong-coupling expansionsDOI: 10.1103/PhysRevB.70.184520ImpactFactor: 3.075Citations: 19data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-24References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here
