WATERLOO, Ont. (Thursday, Feb. 14, 2013) A team of researchers at the University of Waterloo's Institute for Quantum Computing has proposed a new computational model that may become the architecture for a scalable quantum computer.
In a paper to be published in the journal Science this week, the research team of IQC Associate Professor Andrew Childs, post-doctoral fellow David Gosset and PhD student Zak Webb proposes using multi-particle quantum walks for universal computation. In a multi-particle quantum walk, particles live on the vertices of a graph and can move between vertices joined by an edge. Furthermore, nearby particles can interact with each other.
Traditionally, a quantum algorithm is implemented on a register of qubits by actively manipulating the qubits according to a set of desired operations. In this new model, a desired quantum algorithm can be implemented by letting the qubits "quantum walk" on an appropriately chosen graph, without having to control the qubits. The process is analogous to a billiard-ball computer where classical logic gates are performed using collisions.
Many previous quantum-walk experiments have not been scalable. But this new model proposed by Childs and his team identifies the requirements to implement quantum walks so they have the potential for significant quantum speedup, paving the way for scalable future experiments. The model could be naturally realized in a variety of systems, including photons with interactions mediated by superconducting circuits.
Quantum walk-based computing is particularly promising because of its universality. "In principle we can cast any quantum algorithm into this model," says Childs. In future work, Childs and his team are interested in applying the model to develop new quantum algorithms and to study problems in quantum computational complexity.
About the Institute for Quantum Computing (IQC)
The Institute for Quantum Computing (IQC) is a multidisciplinary scientific research institute at the University of Waterloo. Our research focuses on harnessing the quantum laws of nature to discover and develop powerful new technologies that will transform information technology and drive the 21st century economy. IQC research bridges theory and experiments in quantum computing, quantum communication and other quantum devices through the collaboration of over 200 computer scientists, engineers, mathematicians, physical scientists and students. Established in 2002, IQC also offers graduate and post-graduate programs and educational outreach activities that inspire scientific discovery in the realm of quantum mechanics.
About the University of Waterloo
In just half a century, the University of Waterloo, located at the heart of Canada's technology hub, has become one of Canada's leading comprehensive universities with 35,000 full- and part-time students in undergraduate and graduate programs. Waterloo, as home to the world's largest post-secondary co-operative education program, embraces its connections to the world and encourages enterprising partnerships in learning, research and discovery. In the next decade, the university is committed to building a better future for Canada and the world by championing innovation and collaboration to create solutions relevant to the needs of today and tomorrow. For more information about Waterloo, visit www.uwaterloo.ca.
Media contact
Tobi Day-Hamilton
Associate Director, Communications and External Relations
Institute for Quantum Computing
University of Waterloo
http://www.iqc.uwaterloo.ca
Scientific contact
Andrew Childs
Institute for Quantum Computing
University of Waterloo
amchilds@uwaterloo.ca
Journal
Science