%0 Journal Article %T Controlled On-Chip Single-Photon Transfer Using Photonic Crystal Coupled-Cavity Waveguides %A Hubert Pascal Seigneur %A Matthew Weed %A Michael Niklaus Leuenberger %A Winston Vaughan Schoenfeld %J Advances in OptoElectronics %D 2011 %I Hindawi Publishing Corporation %R 10.1155/2011/893086 %X To the end of realizing a quantum network on-chip, single photons must be guided consistently to their proper destination both on demand and without alteration to the information they carry. Coupled cavity waveguides are anticipated to play a significant role in this regard for two important reasons. First, these structures can easily be included within fully quantum-mechanical models using the phenomenological description of the tight-binding Hamiltonian, which is simply written down in the basis of creation and annihilation operators that move photons from one quasimode to another. This allows for a deeper understanding of the underlying physics and the identification and characterization of features that are truly critical to the behavior of the quantum network using only a few parameters. Second, their unique dispersive properties together with the careful engineering of the dynamic coupling between nearest neighbor cavities provide the necessary control for high-efficiency single-photon on-chip transfer. In this publication, we report transfer efficiencies in the upwards of 93% with respect to a fully quantum-mechanical approach and unprecedented 77% in terms of transferring the energy density contained in a classical quasibound mode from one cavity to another. 1. Introduction In order to obtain an efficient quantum computing architecture, the general consensus is that various implementations of the qubit should be combined. This calls on the one hand for stationary qubits that are good for storage, such as atoms to be used at quantum network nodes, and on the other hand for flying qubits that have desirable properties for travel, such as photons to be used as quantum interconnects. Moreover, the storage qubits can map their quantum state onto the traveling qubits and vice versa by means of coherent interfaces [1¨C3]. With the intention of realizing an efficient quantum computing architecture, this composite qubit approach to a quantum technology has been proposed for ion trap qubits [4] and also for neutral atoms [5]. We, in addition, have proposed a similar approach in connection with semiconductor-based artificial atoms or quantum dots [6]. Regardless of choice, these various implementations of the composite qubit architecture are only possible if single photons are able to be guided from one node to another with both high efficiency and fidelity. Recently, the on-chip generation and transfer of microwave single photons have been demonstrated in connection with superconducting qubits via transmission line cavities [7¨C10]. In addition, the %U http://www.hindawi.com/journals/aoe/2011/893086/