Title

Professor

Education

Ph.D. Physics - California Institute of Technology, 1977
B.S. Physics - Purdue University, 1970

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 Bells 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 Bells 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.

Selected Publications

 "Bell Inequality for Position and Time", J.D. Franson, Phys. Rev. Lett. 62, 2205-2208 (1989).

 "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, 4552-4555 (1991).

 "Nonlocal Cancellation of Dispersion", J.D. Franson, Phys. Rev. A 45, 3126-3132 (1992).

 "Nonlocal Reduction of the Wave Function by Quantum Phase Measurements", J.D. Franson, Phys. Rev. A 49, 3221-3227 (1994).

 "Null Result for Enhanced Neutrino Scattering in Crystals", J.D. Franson and B.C. Jacobs, Phys. Rev. A 46, 2235-2239 (1992).

 "Operational System for Quantum Cryptography", J.D. Franson and B.C. Jacobs, Electronics Letters 31, 232-234 (1995).

 "Quantum Cryptography in Free Space", B.C. Jacobs and J.D. Franson, Optics Letters 21, 1854-1856 (1996).

 "Change and Uncertainty in Quantum Systems", J.D. Franson, Physical Review A 54, 3808-3812 (1996).

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

 “Probabilistic Quantum Logic Operations using Polarizing Beam Splitters”, T.B. Pittman, B.C. Jacobs, and J.D. Franson, Physical Review A 64, 062311-1 to 062311-9 (2001).

 “Perturbation Theory for Quantum-Mechanical Observables”, J.D. Franson and M.M. Donegan, Physical Review A 65, 052107-1 to 052107-8 (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, 257902-1 to 257902-4 (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, Physical Review A 68, 032316 (2003).

 “Photon number resolution using time-multiplexed single-photon detectors”, M.J. Fitch, B.C. Jacobs, T.B. Pittman, and J.D. Franson, Physical Review A 68, 043814 (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).

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

 “Generation of Entanglement Outside of the Light Cone”, J.D. Franson, Journal of Modern Optics 55, 2117-2140 (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).