Entanglement and Purcell Effects in Systems for Quantum Information and Sensing
Stephen K. Gray, Argonne National Laboratory
I discuss how to propagate the quantum mechanical density matrix, including dephasing, spontaneous emission and dissipation for systems relevant to quantum information and sensing. Two applications are then presented. In the first example, a plasmonic system is coupled to quantum dots. The plasmonic system could be a single metal nanoparticle or an array of metal nanoparticles and can be viewed as an optical resonator. I show that entanglement between two or more quantum dots can arise via coupling with the plasmon, and how such entanglements can be generated via pulsed optical excitation. The Purcell effect, or enhanced spontaneous emission rate of the quantum dots in the presence of the resonator, plays a role in the underlying mechanism. In the second example, a nitrogen-vacancy or NV center coupled to a mechanical resonator in the form of strain modes of the diamond lattice is considered. A reciprocal Purcell effect is identified as being responsible for a possible means of optically cooling the mechanical resonator.