A non-Markovian optical signature for detecting entanglement in coupled excitonic qubits

¹  Departamento de Física, Universidad de Los Andes - A.A, 4976, Bogotá, Colombia
²  Physics Department, Clarendon Laboratory, Oxford University - Oxford, OX1 3PU, UK

Received: 4 August 2006
Accepted: 23 January 2007

Abstract

We identify an optical signature for detecting entanglement in experimental nanostructure systems comprising coupled excitonic qubits. This signature owes its strength to non-Markovian dynamical effects in the second-order temporal coherence function of the emitted radiation. We calculate autocorrelation and cross-correlation functions for both selective and collective light excitation, and prove that the coherence properties of the emitted light do indeed carry information about the entanglement of the initial multi-qubit state. We also show that this signature can survive in the presence of a noisy environment.