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James Franson

James Franson
Contact Information 
Physics, Rm 314




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 investigating optical approaches to quantum computing and improved methods for quantum key distribution.

Dr. Franson has theoretically predicted several new effects that have now been experimentally observed, including nonlocal interferometry (the Franson interferometer) 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.

Our early work in quantum computing included 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 nonlinear optical effects, such as the use of the quantum Zeno effect to suppress the failure events that would otherwise occur in optical logic gates.

Dr. Franson is also involved in theoretical research in a variety of other areas, including quantum mechanics in curved spacetime and the interface between quantum optics and quantum electrodynamics.

Selected Publications

“Origin of Quantum Noise and Decoherence in Distributed Amplifiers”, J.D. Franson and B.T. Kirby, Phys. Rev. A 92, 053825 (2015).

“Apparent Correction to the Speed of Light in a Gravitational Potential”, J.D. Franson, New J. of Phys. 16, 065008 (2014).

“Beating Classical Computing Without a Quantum Computer”, J.D. Franson, Science 339, 767 (2013).

“Nonlocal Interferometry using Macroscopic Coherent States and Weak Nonlinearities”, B.T. Kirby and J.D. Franson, Phys. Rev. A 87, 053822 (2013).

“A Topological Route to Error Correction”, J.D. Franson, Nature 482, 478 (2012).

“Mathematical Constraint on Functions with Continuous Second Partial Derivatives”, J.D. Franson, J. of Phys. A: Math. and Theor. 45, 045202 (2012).

“Entanglement from Longitudinal and Scalar Photons”, J.D. Franson, Phys. Rev. A 84, 033809 (2011).

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

“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).

“Generation of Entanglement Outside of the Light Cone”, J.D. Franson, J. Mod. Optics 55, 2117 (2008).

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

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

“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).

“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 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).

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

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

“Maxwell Duality, Lorentz Invariance, and Topological Phase”, J.P. Dowling, C.P. Williams, and J.D. Franson, Phys. Rev. Lett. 83, 2486-2489 (1999).

“Experimental Observation of the Splitting of Single Photons by a Beam Splitter”, J.D. Franson, Phys. Rev. A 56, 1800-1805 (1997).

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

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

“Quantum Cryptography Using Optical Fibers”, J.D. Franson and H. Ilves, Appl. Optics 33, 2949 (1994).

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

“Violations of a Simple Inequality for Classical Fields”, J.D. Franson, Phys. Rev. Lett. 67, 290-293 (1991).

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

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

A complete list of publications can be found on our group website.

Relativistic wave packet of an electron moving in curved spacetime.