Co-sponsor Department of Physics

Raymond Laflamme

University of Waterloo Wednesday, January 20, 2016

4:00 PM

Swain Hall, Rm. 119

Coffee will start at 3:30pm

Experimental Quantum Error Correction

Abstract: The last decade has seen the impressive development of quantum information science, both in theory and in experiment. There are many measures that can be used to assess the achievements in the field: new algorithms, new applications and larger quantum processors, to name a few. The discovery of quantum algorithms has demonstrated the potential power of quantum information. To realize this potential requires the ability to overcome the imprecision and imperfection inherent in physical systems.

Quantum error correction (QEC) has provided a solution, showing that errors can be corrected with a reasonable amount of resources as long as their rate is sufficiently small. Implementing QEC protocols remains one of the most important challenges in QIP. In the experimental arena, the quest to build quantum processors that could outperform their classical counterparts has led to many blueprint proposals for potential devices based on NMR, electron spin resonance, ion traps, atom traps, optics, superconducting devices and nitrogen- vacancy centers, among others. Many have demonstrated not only the possibility of controlling quantum bits, but also the ability to do so in practice, showing the progression of quantum information science from the blackboard to the laboratory. My presentation will give an overview of some of the recent results in quantum information science on the way to implement quantum error correction. I will show how noise can be characterized efficiently when our goal is to find suitable quantum error correcting codes. I will show demonstrations of control to implement some quantum error correcting codes and finally how can noise be extracted through algorithmic cooling. I will comments on some challenges that need to be solved and a path towards implementing many round of quantum error correction.

Biography: Prof. Laflamme and his colleague Don Page are responsible for having changed Hawking’s mind on the reversal of the direction of time in a contracting universe (see Hawking’s book, A Brief History of Time). After surviving Part III of the Mathematical Tripos at the University of Cambridge, Raymond Laflamme completed his PhD on aspects of general relativity and quantum cosmology in the Department of Applied Mathematics and Theoretical Physics (DAMTP) under the direction of Stephen Hawking. Laflamme is originally from Québec City, where he studied Physics as an undergraduate at the Université Laval. From 1988-1992, Laflamme held a Killam Postdoctoral fellowship at UBC, and a Postdoctoral fellowship at Peterhouse College, University of Cambridge. From 1992-2001, Prof. Laflamme worked as a research scientist at Los Alamos Research Laboratory, where his interests shifted from cosmology to quantum computing.

Since the mid-1990s, Laflamme has developed theoretical approaches to quantum error correction, and has conducted experimental demonstrations of these techniques. In collaboration with Emmanuel Knill, Laflamme gave conditions for quantum error correcting codes, and established the fault-tolerance threshold, thereby showing that quantum computing systems could be practically useful. With colleagues, he has developed a blueprint for a quantum information processor using linear optics, and devised and implemented new methods to for making quantum information robust against corruption in both cryptographic and computational settings. In 2001, Laflamme returned to Canada as the founding Executive Director of the Institute for Quantum Computing (IQC), and as a founding member of the Perimeter Institute For Theoretical Physics. Dr. Laflamme is the founding Scientific Director of Quantum Works, Canada’s national research consortium on quantum information science, and has been Director of the Quantum Information Program at the Canadian Institute for Advanced Research (CIFAR) since 2003, and a CIFAR Fellow since 2001. Dr. Laflamme holds the Canada Research Chair in Quantum Information, and is a Professor in the Department of Physics and Astronomy at the University of Waterloo. He is also the CSO for Universal Quantum Devices and a Scientific Advisor for Quantum Valley Investments.

Dr. Laflamme has achieved the long-standing world record for the largest quantum computer achieved to date, at 12 qubits.