WATERLOO, Ont. (Wednesday, Nov. 3, 2010) - A research team at the University of Waterloo's Institute for Quantum Computing has taken an important step forward in measurement-based quantum computing, describing their results in the most recent edition of Nature Physics.
In the IQC quantum optics lab, the researchers created and characterized, for the first time, a so-called AKLT (Affleck-Kennedy- Lieb-Tasaki) state, which can serve as a quantum processor. AKLT states are attractive for measurement-based quantum computing because they can be obtained simply by cooling the right solid-state system down to very low temperatures.
Although present-day technology is unable to realize and address the components of an AKLT state in a solid, the IQC researchers devised the means to simulate the AKLT state by using properties of photons, the fundamental particles of light.
The experiment demonstrates the viability of quantum computation using AKLT states, and will inform future work in condensed matter physics.
The experiment "capitalized on the fact that photonic states can simulate other quantum systems," said Jonathan Lavoie, a PhD student at IQC and co-author of the paper.
The team experimentally achieved a result that had previously been theoretically considered as a resource for measurement-based (or "one- way") quantum computing.
"Our experiment is bridging the gap between condensed matter physics and quantum information," said Kevin Resch, an IQC faculty member and professor in the University of Waterloo's physics and astronomy department. "That's an important area to explore."
Co-authors on the Nature Physics paper, entitled "Optical one-way- quantum computing with a simulated valence-bond solid," included IQC researchers Rainer Kaltenbaek and Bei Zeng, along with Stephen Bartlett of the University of Sydney.
In a News and Views article published in the same issue of Nature Physics, physicist Robert Raussendorf lauds the IQC team's discovery as a crucial step forward in the development of measurement-based quantum computing.
"The proof-of-principle AKLT measurement-based quantum computer has arrived," writes Raussendorf, a faculty member at the University of British Columbia.
While Raussendorf points out that more work still lies ahead (such as using entangled logical qubits, and eventually the actual creation of AKLT states by cooling), he concludes that the IQC team's work is cause for optimism: "Now watch out for the prototype!"
About Waterloo
The University of Waterloo, located at the heart of Canada's Technology Triangle, is one of Canada's leading comprehensive universities. Waterloo is home to 30,000 full- and part-time undergraduate and graduate students who are dedicated to making the future better and brighter. Waterloo, known for the largest post- secondary co-operative education program in the world, supports enterprising partnerships in learning, research and discovery. For more information about Waterloo, visit www.uwaterloo.ca.
