Real Time Imaging of Quantum and Thermal Fluctuations: a Detour into Quantum Noise
Mon, Dec. 02nd 2013, 14:30
Salle Claude Itzykson, Bât. 774, Orme des Merisiers
In the last decade progresses have been achieved in realising and manipulating stable and controllable quantum systems, and these made possible to experimentally study fundamental questions posed in the early days of quantum mechanics. We shall theoretically discuss recent cavity QED experiments on non-demolition quantum measurements. While they nicely illustrate the possibility to implement efficient quantum state manipulations, these experiments pose a few questions such as: What does it mean to observe a progressive wave function collapse in real time? How to describe it? What do we learn from them? Their analysis will allow us on the one hand to link these experiments to basics notions of probability or information theory, and on the other hand to touch upon notions of quantum noise. As an illustration, we shall also look at quantum systems in contact with a heat bath and we shall describe the main physical features of thermally activated quantum jumps.