Work Address
Communication Sciences Institute
Ming Hsieh Department of Electrical Engineering
University of Southern California
3740 McClintock Ave, EEB 502
Los Angeles, CA 90089
phone: (213) 740-3503
FAX: (213) 740-8729
email: tbrun@usc.edu
Home page: http://ee.usc.edu/faculty_staff/faculty_directory/brun.htm
Education:
Ph.D. in Physics, California Institute of Technology, April 1994.
Thesis Advisor: Prof. Murray Gell-Mann
Thesis Title: Applications of the Decoherence Formalism.
M.S. in Physics, Caltech, June 1991.
A.B. Cum Laude in Physics, Harvard University, June 1989.
Research Interests:
Quantum information theory and quantum computation, especially the effects of noise and decoherence on quantum information processing; detailed modeling and numerical simulation of physical implementations; quantum entanglement; applications of quantum computers to simulations of quantum systems.
Work Experience:
Associate Chair, Ming-Hsieh Department of Electrical Engineering, USC, 2007-Present
- Supervise graduate student affairs: PhD and MS admissions, TA assignments, fellowship nominations, VIP and MS Honors programs, academic requirements and disciplinary issues. Serve in absence of Chair.
Associate Professor, Ming Hsieh Department of Electrical Engineering, USC, 2006-Present
Communication Sciences Institute
University of Southern California
3740 McClintock Ave, EEB 502
Los Angeles, CA 90089
- Worked on fault-tolerance for holonomic computation. (With student Ognyan Oreshkov and colleague Daniel Lidar.)
- Generalized work on decomposing generalized measurements into weak measurements to continuous processes with more than two outcomes. (With student Martin Varbanov.)
- Developed technique for measuring weak values. (With Lajos Diósi and Walter Strunz.)
- Proved private capacity regions for secret-key-assisted quantum communication. (With students Min-Hsiu Hsieh and Zhicheng Luo.)
- Worked on continuous error correction for non-Markovian errors, and general conditions for correctability. (With student Ognyan Oreshkov.)
- Found that for symmetric graphs, the quantum walk is often effectively confined to a smaller quotient graph. Generalized to continuous-time walks on graphs (With students Hari Krovi and Martin Varbanov.)
- With Igor Devetak, worked on entanglement-assisted quantum error-correcting codes. Extended this to catalytic codes and entanglement-assisted operator quantum error-correcting codes. Found quantum LDPC codes which utilize only small amounts of entanglement. Generalized to quantum convolutional codes and classically-enhanced codes. (With students Min-Hsiu Hsieh, Mark Wilde, and Isaac Kremsky.)
- Simulated single-photon sources composed of a quantum dot in an optical microcavity, including electronic pumping and monitoring of the dot. (With student Shesha Raghunathan.)
- Simulated performance of codes in noisy channels, with application to optical fiber quantum communication and fault-tolerant computation. (With student Bilal Shaw.)
- Developed continuous-variable equivalent of coherent bit (“cobit”) channel, and determined performance loss due to finite squeezing. Generalized entanglement-assisted codes to continuous variables. (With students Mark Wilde and Hari Krovi.)
- Investigated quantitative measure of state assignment compatibility, and procedure for pooling information in two quantum states. (With student Min-Hsiu Hsieh.)
Assistant Professor, Electrical Engineering Systems, USC, 2003-2006
Communication Sciences Institute
University of Southern California
3740 McClintock Ave, EEB 502
Los Angeles, CA 90089
- Evolved a scheme for measuring nonlinear functions of quantum states.
- Proved that all generalized measurements can be decomposed into weak measurements, and derived explicit decompositions. (With students Ognyan Oreshkov.)
- Found differential conditions for entanglement monotones, and identified a new polynomial monotone for three-qubit pure states. (With student Ognyan Oreshkov.)
- Found an analytical expression for the hitting time of a general quantum walk, and showed that for the walk on the hypercube the hitting time can be infinite; extended this result to walks on any graph with sufficient symmetry. (With student Hari Krovi.)
- Continued work on Magnetic Resonance Force Microscopy with Hsi-Sheng Goan. (With student Shesha Raghunathan.)
- Updated and revised software for simulating open quantum systems. (With student Bilal Shaw.)
- Continued work on signatures of quantum chaos with Rüdiger Schack, Carlton Caves, and Andrew Scott.
Member, School of Natural Sciences, 2000-2003
Institute for Advanced Study
Einstein Drive
Princeton, NJ 08540
- Studied the quantum-to-classical transition for quantum random walks, finding an exact criterion for classical behavior in the long-time limit, in collaboration with Andris Ambainis and Hilary Carteret.
- In collaboration with Hsi-Sheng Goan, developed detailed model of Magnetic Resonance Force Microsccopy for single spin measurement.
- Investigated convergence and conservation properties of stochastic Schrödinger equations, and their relativistic extensions, in collaboration with Stephen Adler, Lane Hughston and Dorje Brody.
- Worked on Bayesian reasoning in quantum information theory, with application to entanglement distillation of unknown states; co-discovered a criterion for differing states to describe the same quantum system.
- Developed a quantum trajectory model using quantum bits, and used this to quantify information exchange rates in open systems.
- Continued study of multipartite quantum entanglement; discovered a class of “quantum web” states, and identified a set of entanglement monotones, the entanglements of preparation.
- Collaborated with Rüdiger Schack on qubit models for quantum chaos.
Postdoctoral Researcher 1998-2000
Department of Physics
Carnegie Mellon University
Pittsburgh, PA 15213-3890
Supervisor: Prof. Robert B. Griffiths
- Continued to work in the formalism of consistent histories, with particular application to hydrodynamic variables and relativistic quantum histories.
- Worked on understanding the physical basis of quantum information theory, especially the nature of entanglement and its quantification in multipartite systems, in collaboration with Oliver Cohen.
- Proposed a hybrid solid-state/optical implementation of quantum computation in collaboration with Hailin Wang.
- Further studied the connections between consistent histories and quantum trajectories, with particular emphasis on the importance of generalized records.
- Worked on Bayesian probabilities in quantum information in collaboration with Rüdiger Schack and Carlton Caves.
Visiting Postdoctoral Researcher 1996-1998
Institute for Theoretical Physics
University of California
Santa Barbara, CA 93106-4030
Supervisor: Prof. James B. Hartle
- Continued to work in the formalism of decoherent (consistent) histories, with particular application to the histories of hydrodynamic variables;
- Performed simulations of decoherence in quantum computers and its effect on fault-tolerant error correction schemes;
- Analytically studied the long-term behavior of quantum jump trajectories, in collaboration with Luiz Davidovich;
- Performed simulations of quantum chaotic systems realized on quantum computers, in collaboration with Rüdiger Schack.
Postdoctoral Fellow 1994-96
Department of Physics
Queen Mary and Westfield College
London E1 4NS, UK
Supervisor: Prof. Ian Percival
- Worked on the quantum trajectories picture of quantum mechanics, including quantum state diffusion (QSD) and quantum jumps (QJ), and wrote a C++ software library to simulate quantum systems with quantum trajectories;
- Studied the relationship between decoherent histories and quantum trajectories;
- Applied these techniques to a variety of problems, including quantum dissipative chaos, calculating quantum optical time correlation functions and spectra, continuous measurement, quantum computation, and laser models;
- Developed a model demonstrating the decoherence of hydrodynamic variables;
- Studied the effects of decoherence on quantum computation and examined schemes for quantum error correction;
- Studied the rise of the classical limit of quantum mechanics.
Research Assistant, 1990-94
Department of Physics
Caltech
Pasadena, CA 91125
Supervisor: Prof. Murray Gell-Mann
- Worked on applications of the decoherence formalism, including nonlinear Brownian motion, quantum dissipative chaos, and ideas of classicality;
- Studied complex systems, and worked on models exhibiting Zipf’s scaling law;
- Studied quantum cosmology, and the application of decoherence to minisuperspace models.
Teaching Assistant, 1990-94
Department of Physics
Caltech
Pasadena, CA 91125
- Taught basic numerical methods to physics students.
Research Assistant, summers of 1986, 1987, 1988
Laboratory of Computational Physics and Fluid Dynamics
Naval Research Laboratory
Washington, DC
- Wrote graphics packages for fluid flow simulations, including models of explosions;
- Developed algorithm for integrating large numbers of ordinary differential equations, for use in simulations of burning gasses;
- Developed a new numerical algorithm to model low-energy scattering from thin sheets of crystal;
- Disproved a conjecture in the theory of magnetic flux diffusion.
Computer Programmer, school years of 1986-87, 1987-88, 1988-89
Neuroendocrinology Laboratory
Harvard Medical School
Boston, MA
- Wrote programs for the storage, compaction, display, and scoring of EEG sleep data;
- Miscellaneous other software development.
Scholarships, Prizes, and Awards:
Harvard College Scholarship, John Harvard Scholarship. Caltech Graduate Fellowship. Nominated for Stemple Prize, for best research by a physics grad student at Caltech. Martin A. and Helen Chooljian Membership in Natural Sciences, Institute for Advanced Study. Zumberge Grant for Innovation, USC. NSF Early Career Award. Senior Member of IEEE.
Service
- Associate Editor of IEEE Transactions on Computers.
- Associate Editor of Journal of Computer and System Sciences.
- Editorial Board, Journal of Physics A.
- Editorial Board, Physical Review A.
- Associate Chair, Electrical Engineering Department.
Invited Talks and Lectures:
Talk at the Third Santa Fe Workshop on Complexity, Entropy and the Physics of Information, 15-19 May 1994, Santa Fe, New Mexico.
Talks at the One-day Meeting on Quantum Theory, Imperial College, 1 April 1996, London, England, and at the Mini-Workshop on Information Physics, University of New Mexico, 30 April 1997.
Talk at 1997 Annual Meeting of the Optical Society of America, Long Beach, California.
Colloquium at the University of Missouri (Columbia), 1998.
Colloquium at Southern Illinois University (Carbondale), 1998.
Talk at 1999 workshop on Complexity, Computation and the Physics of Information, Isaac Newton Institute, Cambridge University.
Colloquium at the University of Chicago, 2000.
Talk at 2nd International Conference on Probability and Physics, Växjö, Sweden, June 2002. Talk at QCMC 2002, MIT, July 2002.
Talk at DICE, Piombino, Italy, September 2002.
Colloquium at University of Southern California, 2004.
Colloquium at University of Arkansas, 2004.
Talk at QCMC 2004, Strathclyde, July 2004.
Talk at 1st Asia-Pacific Conference on Quantum Information Science, 2004.
Lectures at SQuInT Student Summer School and Retreat, July 2005. (Local organizer).
Talk at BBQW 2005, Konstanz, Germany, August 2005.
Talk at QUEST 2005, Santa Fe, New Mexico, August 2005.
Colloquium, CSU Long Beach, October 2005.
Talk at CQIQC-II, Toronto, August 2006.
Co-organizer of First International Conference on Quantum Error Correction, December 2007 (QEC07). (Also gave a talk.)
Invited tutorial, APS March Meeting 2008.
Numerous other talks and seminars at many locations, including Caltech, The Naval Research Laboratory, Los Alamos National Laboratory, The University of New Mexico (Albuquerque), The University of California at Santa Barbara, Queen Mary and Westfield College, Imperial College, Oxford University, Royal Holloway College, The University of Geneva, L’Ecole de Physique Théorique des Houches, The Institute for Theoretical Physics (Santa Barbara), Carnegie Mellon University, The University of Oregon (Eugene), The Institute for Advanced Study, The Santa Fe Institute, The University of Southern California, National Taiwan University (Taipei, Taiwan), National Cheng-Kung University (Tainan, Taiwan), and Tsinghua University (Beijing, China).
Last updated: 30 December 2008.