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James Franson

James Franson
Contact Information
jfranson@umbc.edu 
410-455-8115
Physics, Rm 314

Title

Professor

Education

Ph.D. Physics – California Institute of Technology, 1977

Previous Experience

Dr. Franson was previously a member of the Principal Professional Staff at the Johns Hopkins University Applied Physics Laboratory and Research Professor in the Johns Hopkins Electrical and Computer Engineering department.

Professional Interests

Quantum information processing is a rapidly growing field of research with fundamental implications as well as potential practical applications.  We are actively involved in an optical approach to quantum computing and we have done work in quantum key distribution as well.

Our work in quantum computing includes the development of linear optical approaches for quantum logic gates.  In this approach, quantum logic gates are implemented by using the quantum measurement process to project the state of two input qubits into the desired output state, such as a controlled-NOT operation.  This avoids the need for a nonlinear medium to produce the required interaction between the two input qubits, but it also gives a large increase in the number of resources required to implement the logic gates.  Our more recent work makes use of the quantum Zeno effect to suppress the failure events that would otherwise occur in linear optics logic gates.

We also do research in a variety of other areas of quantum optics, especially topics related to entanglement and violations of Bell’s inequality.  For example, we recently introduced the concept of photon holes in analogy with the holes of semiconductor theory, and showed that the photon holes can be entangled and violate Bell’s inequality.   Entangled photon holes may also be a promising method for secure quantum communications.

Basic issues in the foundations of quantum optics are also being investigated, including the interface between quantum optics and quantum electrodynamics.

Dr. Franson has theoretically predicted several new effects that have now been experimentally observed, including nonlocal interferometry and nonlocal dispersion cancellation.   His group was one of the first to demonstrate quantum cryptography in optical fibers and the first to demonstrate it in free space.  We were also the first to demonstrate quantum logic operations for photonic qubits, including the first CNOT gate.  Dr. Franson is a Fellow of the American Physical Society and the Optical Society of America.

Selected Publications

“Bell Inequality for Position and Time”, J. D. Franson, Phys. Rev. Lett. 62,  2205 (1989).

“Two-Photon Interferometry over Large Distances”, J.D. Franson, Phys. Rev. A 44, 4552 (1991).

“Nonlocal Cancellation of Dispersion”, J.D. Franson, Phys. Rev. A 45, 3126 (1992).

“Quantum Cryptography Using Optical Fibers”, J.D. Franson and H. Ilves, Appl. Optics33, 2949 (1994).

“Quantum Cryptography in Free Space”, B. C. Jacobs and J. D. Franson, Optics Lett.21, 1854 (1996).

“Coherent Splitting of Single Photons by an Ideal Beam Splitter”, J. D. Franson, Phys. Rev. A 53, 3756 (1996).

“Probabilistic Quantum Logic Operations using Polarizing Beam Splitters”, T. B. Pittman, B. C. Jacobs, and J. D. Franson, Phys. Rev. A 64, 062311 (2001).

“Perturbation Theory for Quantum-Mechanical Observables”, J. D. Franson and M. M.  Donegan, Phys. Rev. A 65, 052107 (2002).

“Demonstration of Nondeterministic Quantum Logic Operations Using Linear Optical Elements”, T. B. Pittman, B. C. Jacobs, and J. D. Franson, Physical Review Letters 88, 257902 (2002).

“Experimental Controlled-NOT Logic Gate for Single Photons in the Coincidence Basis”, T.B. Pittman, M.J. Fitch, B.C. Jacobs, and J.D. Franson, Phys. Rev. A 68, 032316 (2003).

“Quantum Computing using Single Photons and the Zeno Effect”, J.D. Franson, B.C. Jacobs, and T.B. Pittman, Phys. Rev. A 70, 062302 (2004).

“Experimental Demonstration of a Quantum Circuit using Linear Optics Gates”, T.B. Pittman, B.C. Jacobs, and J.D. Franson, Phys. Rev. A 71, 032307 (2005).

“Entangled Photon Holes”, J.D. Franson, Phys. Rev. Lett. 96, 090402 (2006).

“Zeno Logic Gates Using Microcavities”, J.D. Franson, B.C. Jacobs, and T.B. Pittman, J. Optical Soc. Of America. B 24, 209 (2007).

“Generation of Entanglement Outside of the Light Cone”, J.D. Franson, J. Mod. Optics55, 2117 (2008).

“All-optical switching using the quantum Zeno effect and two-photon absorption”, B.C. Jacobs and J.D. Franson, Phys. Rev. A 79, 063830 (2009).

“Pairs Rule Quantum Interference”, J.D. Franson, Science 329, 396 (2010).

A plot of the Feynman propagator, which is proportional to the probability amplitude to emit a photon at one location and annihilate it at another location. This plot corresponds to a one nanosecond delay after a photon was emitted at the origin.

A plot of the Feynman propagator, which is proportional to the probability amplitude to emit a photon at one location and annihilate it at another location. This plot corresponds to a one nanosecond delay after a photon was emitted at the origin.