Entanglement Dynamics for three and more Excitons in a Strained Graphene Sheet, embedded in a microcavity*

We present a numerical analysis of the quantum entanglement between three and more qubits consisting of excitons in a strained graphene sheet, embedded in an optical microcavity. We analyze the time evolution of the entanglement for the system by calculating the time evolution of the negativity and the three-pi for the three-qubit case, both with and without cavity decay. We also provide a framework for the N-qubit entanglement analysis. Special attention is given to the evolution of the entanglement when the system starts out in the Greenberger-Horne-Zeilinger (GHZ) state, which is a strongly entangled state between three qubits with no pairwise entanglement.