title: Orbital magnetization as a local property.
abstract: The modern expressions for polarization P and orbital magnetization M are k-space integrals. But a genuine bulk property should also be expressible in r space, as an unambiguous function of the ground-state density matrix, "nearsighted" in insulators, independently of the boundary conditions--either periodic or open. While P--owing to its "quantum" indeterminacy--is not a bulk property in this sense, M is. We provide its r-space expression for any insulator, even with a nonzero Chern invariant. Simulations on a model Hamiltonian validate our theory.
authors.affiliation: Dipartimento di Fisica, Università di Trieste, 34127 Trieste, Italy.
authors.forename: Raffaello
authors.initials: R
authors.lastname: Bianco
authors.forename: Raffaele
authors.initials: R
authors.lastname: Resta