Quantum Information Processing and Quantum Communications

Linear Optics and Projective Measurements for Fun and Profit!

aula DOTTORATO- Mercoledì 28 aprile ore 16.00
  JONATHAN P. DOWLING, Nasa Jet Propulsion Laboratory, California Institute of Technology

>VITAE: Jonathan P. Dowling is group supervisor
at the Jet Propulsion Laboratory of Pasadena, is expert of theoretical quantum optics, quantum information theory, laser physics, and mathematical physics. He worked for Army Aviation & Missile Command from 1990 through 1998, serving on numerous Department of Defense Review Boards and Organizational Committees, for the Army Research Office (ARO),
the Defense Advanced Projects Research Agency (DARPA), and the National Security Agency (NSA), on topics such as Photonic Band-Gap Materials, Quantu Cryptography and Computing, The Atom Laser, Information Technology, Atomic, Molecular, and Optical Physics and General Relativity. In particular he made relevant studies on Relativistic Effects in the Global Positioning System.

Jonathan P. Dowling
  It has been know for some time - see Kimble - that strong optical nonlinearities, such as those generated in cavity QED, are sufficient for making the photon-photon interactions required for scalable photonic quantum computing. Recent work of Knill, LaFlamme, and Milburn (KLM), shows us that scalable quantum computing with photons may also be had by exploiting only linear optics and projective measurements, but no explicit nonlinearities. The question naturally arises, “In what way are projective measurements like optical nonlinearities?” I will discuss a general scheme by which we may take an arbitrary projective measurement protocol and from it extract the equivalent set up with effective optical nonlinearities. I will also discuss applications of such schemes to quantum information processing devices, such as repeaters, as well as to optical quantum metrology.