Controlling isolated quantum particles

The lecture originally planned was on the measurement of time in quantum physics. Circumstances have led to a change of theme. However, several seminars, including one by David Wineland (NIST), will deal with atomic clocks and their applications.

The lecture will focus on the measurement and manipulation of isolated quantum particles, the field of physics recognized by the 2012 Nobel Prize, awarded for parallel research carried out at the ENS's Kastler Brossel laboratory and the National Institute of Standards and Technology (NIST) in Boulder, USA.
We'll start by recalling the general principles governing the manipulation of trapped ions or photons, highlighting the similarities between these two types of experiment. An important part of the lecture will then be devoted to the work carried out at ENS on the control of photons in a cavity. First, we'll give an overview of the history of these experiments since they were first developed in the 1970s. We will then describe non-destructive photon counting and studies on Schrödinger cats of light and their decoherence. The deterministic production of entanglement between atoms and photons and the demonstration of simple quantum information operations will then be analyzed. Finally, we will outline the experiments carried out with trapped ions in the NIST laboratory, and conclude with some generalizations of these studies to other systems.