Atoms and Photons - Their Interaction Dynamics

TL;DR

This paper explores the Jaynes-Cummings model's dynamics, extends entanglement schemes for cavity systems, and analyzes how thermal states affect quantum teleportation fidelity.

Contribution

It derives the Rabi model Hamiltonian, extends entanglement schemes to thermal states, and applies these to quantum teleportation with temperature-dependent fidelity.

Findings

Extended entanglement scheme achieves >0.75 success probability

Fidelity decreases with increasing temperature

Scheme enables near-Bell state generation

Abstract

The Jaynes-Cummings model (JCM) describes the interaction of a two-level atom with a single quantised field mode in an optical cavity. In this BSc project we derive the basic Rabi model Hamiltonian and show how it leads to the JCM Hamiltonian. The results are then used to analyse the general time evolution of a bipartite atom-field system and its properties, such as entanglement. We extend a scheme developed by Browne and Plenio [D. Browne and M. B. Plenio, Physical Review A, vol. 67, no. 1, Jan. 2003.] to entangle two cavities that interact with an atom. Our scheme allows to produce states that are arbitrarily close to a Bell state with a success probability greater than 0.75, whereas the success rate of the original method tends to 0 for perfect fidelity. Further, we extend both schemes by allowing the atom or the cavity to be in a thermal state and find that the fidelity of the produced states is reduced with increasing temperature. Finally, we apply our scheme to quantum teleportation, where we find that the fidelity of the teleported state compared to the original state also decreases as the temperature is increased.