PHYSICS COLLOQUIUM
Speaker: Dr. E. Polzik Center for Quantum Optics, Dept. of Physics and Astronomy, University of Aarhus, DK
Date: Wednesday, January 26, 2005
Time: 16:45 h (coffee/tea at 16:15 h in front of auditorium)
Place: ETH Hönggerberg, HPV G4
Title: Quantum memory for light: can the immeasurable be remembered?
Abstract:
A weak pulse of light, the carrier of today's classical communications, is a quantum object. Its amplitude (photon number) and color (phase) cannot be measured with high accuracy due to the Heisenberg uncertainty principle. This complementarity of amplitude and phase of light is widely used in the emerging area of quantum information and quantum communication. Both state-of-the-art classical, and quantum communication networks require memory for light, which in this case has to be a quantum memory. The quantum memory must be capable of storing both an amplitude and a phase of the light pulse, i.e., two immeasurable, complementary variables. In the recent experiment [1] we have demonstrated such a memory. Its principles and directions for future development will be discussed in the talk. [1] B. Julsgaard, J. Sherson, J. I. Cirac, J. Fiurasek, and E. S. Polzik. Nature, November 25 (2004), preprint quant-ph/04100