Physical Review A
Berry’s phase and loops in parameter space
Franco Salmistraro
Abstract
For a quantum system we consider the evolution induced through a Hamiltonian H(R) by an arbitrary closed curve in the space of parameters R. By a proper choice of the basis in the Hilbert space of states, it is shown that one can associate a geometrical phase to each eigenvector of the Hamiltonian. The special cases of adiabatic and cyclic evolution of the state vector are discussed.