The principal collaborators, past and present, are:
The goals of the project are to establish designs for scalable quantum computers in the presence of both hard and soft defects. Scalability is greatly assisted by the principles of quantum communication, that is, the use of heralded long-distance entanglement generation and purification, in conjunction with quantum teleportation, to establish a large-scale cluster state in an inhomogeneous lattice of qubits coupled by nanophotonic structures. Inhomogeneity arises from the presence of defective devices and the need to traverse different distances on a microchip or between different microchips. Using communication concepts, we hope to merge the concepts of topological fault tolerance defined via cluster states of memory qubits with emerging quantum control techniques for quantum dots, solid-state impurities, and cavity QED.An example architecture is shown below:
Details about the function of this architecture are found in Ref. .
Experimental efforts in the Yamamoto group supporting this architecture include the initialization, coherent manipulation, and detection of single spins; for example see Ref. . These methods are being extended to multiple qubits in the laboratory; work in large-scale architecture has the goal to indicate the criteria to be met by these experimental developments to support a scalable device.
An example device, etched using the methods described in Ref. , is shown as the background of this web page.
A foundation of the communication considerations arises from the development of quantum repeaters, as described in Ref. .
 "Distributed Quantum Computation Architecture Using Semiconductor Nanophotonics", R. Van Meter, T. D. Ladd, A. G. Fowler, and Y. Yamamoto (2009),arXiv:0906.2686, available online.
 "Complete quantum control of a single quantum dot spin using ultrafast optical pulses", D. Press, T.D. Ladd, B. Zhang, and Y.Yamamoto, Nature 456, 218 (2008), available online.
 "Monolithic integration of quantum-dot-containing microdisk microcavities coupled to air-suspended waveguides", S. Koseki, B. Zhang, K. De Greve, and Y.Yamamoto, Appl. Phys. Lett. 94, 051110 (2009), available online.
 “System design for a long-line quantum repeater,” R. Van Meter, T. D. Ladd, W. J. Munro, andKae Nemoto, IEEE/ACM Transactions on Networking 17, 1002 (2009), available online.
Page last modified by Thaddeus Ladd, Sept. 18, 2009.