title: Quantum fidelity in the thermodynamic limit.
abstract: We study quantum fidelity, the overlap between two ground states of a many-body system, focusing on the thermodynamic regime. We show how a drop in fidelity near a critical point encodes universal information about a quantum phase transition. Our general scaling results are illustrated in the quantum Ising chain for which a remarkably simple expression for fidelity is found.
authors.affiliation: Los Alamos National Laboratory, Theoretical Division, MS B213, Los Alamos, New Mexico 87545, USA.
authors.forename: Marek M
authors.initials: MM
authors.lastname: Rams
authors.forename: Bogdan
authors.initials: B
authors.lastname: Damski