Geometric Phase in a Quantum Open System

FERNANDO C. LOMBARDO, AND PAULA I. VILLAR

Benasque

Workshop; Workshop on quantum coherence and decoherence; 2010

Centro de Ciencias de Benasque, Pedro Pascual

   We calculate the geometric phase of a bipartite two-level system coupled to an external environment. Weanalyze the reduced density matrix for an arbitrary initial state of the composite system and compute thecorrection to the unitary geometric phase through a kinematic approach. In all cases considered, we observe asimilar structure as a function of the degree of the entanglement of the initial state. Further, we compute theentanglement entropy and concurrence of the bipartite state and analyze if there is any relation among thesequantities and the geometric phase acquired during the nonunitary system’s evolution. Finally, we discuss theresults obtained.