Processing information quantum mechanically is known to enable new communication and computational scenarios that cannot be accessed with conventional information technology (IT). We present here a new approach to scalable quantum computing---a "qubus computer"---which realizes qubit measurement and quantum gates through interacting qubits with a quantum communication bus mode. The qubits could be "static" matter qubits or "flying" optical qubits, but the scheme we focus on here is particularly suited to matter qubits. Universal two-qubit quantum gates may be effected by schemes which involve measurement of the bus mode, or by schemes where the bus disentangles automatically and no measurement is needed. This approach enables a parity gate between qubits, mediated by a bus, enabling near-deterministic Bell state measurement and entangling gates. Our approach is therefore the basis for very efficient, scalable QIP, and provides a natural method for distributing such processing, combining it with quantum communication.

Date Published: 29 August 2006
PDF: 9 pages
Proc. SPIE 6305, Quantum Communications and Quantum Imaging IV, 63050D (29 August 2006); doi: 10.1117/12.675938

Published in SPIE Proceedings Vol. 6305:
Quantum Communications and Quantum Imaging IV
Ronald E. Meyers; Yanhua Shih; Keith S. Deacon, Editor(s)