title: Ground-state fidelity and bipartite entanglement in the Bose-Hubbard model.
abstract: We analyze the quantum phase transition in the Bose-Hubbard model borrowing two tools from quantum-information theory, i.e., the ground-state fidelity and entanglement measures. We consider systems at unitary filling comprising up to 50 sites and show for the first time that a finite-size scaling analysis of these quantities provides excellent estimates for the quantum critical point. We conclude that fidelity is particularly suited for revealing a quantum phase transition and pinning down the critical point thereof, while the success of entanglement measures depends on the mechanisms governing the transition.
authors.affiliation: Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Buonsante
authors.forename: A
authors.initials: A
authors.lastname: Vezzani