Bright and dark periods in the entanglement dynamics of interacting qubits in contact with the environment

Abstract

Interaction among qubits is the basis to many quantum logic operations. We report how such inter-qubit interactions can lead to new features, in the form of bright and dark periods in the entanglement dynamics of two qubits subject to environmental perturbations. These features are seen to be precursors to the well-known phenomenon of sudden death of entanglement (Yu and Eberly 2004 Phys. Rev. Lett. 93 140404 ) for noninteracting qubits. Further, we find that the generation of bright and dark periods is generic and occurs for wide varieties of environment models. We present explicit results for two popular models.