Towards Quantum Control of Quantum Information Systems

Lorenza Viola, Department of Physics and Astronomy, Dartmouth College

Friday, April 18, 2008

Spanos Auditorium

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This seminar is part of the Jones Seminars on Science, Technology, and Society series

Developing theoretical and practical methodologies for accurately controlling the dynamics of quantum systems is a challenge of growing significance across contemporary physics, engineering, and quantum information sciences. While quantum control theory is relatively well established for closed quantum systems undergoing unitary dynamics, realistic situations unavoidably entail control of open quantum systems whose dynamics is non-unitary due to interaction with the environment. After providing the essential background on quantum control systems, I will focus on quantum stabilization problems in two distinct complementary settings: open-loop dynamical decoupling methods for non-Markovian quantum evolutions, and continuous-time output-feedback for Markovian master equations. In particular, I will survey recent results on dynamical control of electron spin decoherence in semiconductor quantum dots, as well as outline Markovian feedback-control strategies for quantum pure state stabilization and decoherence-free subspace synthesis.

About the Speaker

Lorenza Viola obtained a Ph.D. in physics from the University of Padova, Italy, in 1996. After holding a postdoctoral appointment with the Department of Mechanical Engineering at the Massachusetts Institute of Technology from 1997 to 2000, she has been a J.R. Oppenheimer Fellow with the Computer and Computational Sciences Division at Los Alamos National Laboratory. In 2004, she joined the faculty of the Department of Physics and Astronomy at Dartmouth College as an Associate Professor. Over the last ten years, Dr. Viola's research has addressed a broad range of issues within theoretical quantum information physics, with emphasis on modeling and control of complex quantum-dynamical systems. In particular, she has been a key contributor to the development of error-control techniques for open quantum systems based on dynamical decoupling methods, and a proposer of the notion of a noiseless subsystem as a general pathway to protected realizations of information in physical systems. Dr. Viola is a member of the editorial board of 'Physical Review A' as well as a board member of the 'International Physics and Control Society'. Currently, she is also serving as the Chair of the Topical Group on Quantum Information of the American Physical Society.