Fases Geométricas por Integrais de Trajetória
Marcelo da Cunha Arcoverde Alves
Abstract
We study the time evolution of a quantum system under the adiabatic condition using the path integral formulation. We reobtain Berry's phase for systems with nondegenerate and degenerate energy spectra, recovering the well-known results on the literature, and we verify the behavior of the phases under a change of basis of the energy instantaneous eigenstates. We also present a simple derivation of the Adiabatic Theorem[1] using the current notation. We have a comparative summary between the Schrodinger's and the Heisenberg's pictures when the quantum system is driven by a time-dependent hamiltonian and we show how to aply the Adiabatic Theorem to any operator in the Heisenberg's picture that evolves under adiabactic conditions.