Juggling with photons and raising Schrödinger cats of light in a cavity
Prof Serge Haroche, Collège de France, Paris, France
The founders of quantum theory assumed in "thought experiments" that they were manipulating isolated quantum systems obeying the counterintuitive laws which they had just discovered. Technological advances have recently turned these virtual experiments into real ones by making possible the actual control of isolated quantum particles. Many laboratories are realizing such experiments, in a research field at the frontier between physics and information science. Fundamentally, these studies explore the transition between the microscopic world ruled by quantum laws and our macroscopic environment which appears "classical". Practically, physicists hope that these experiments will result in new technologies exploiting the strange quantum logic to compute, communicate or measure physical quantities better than what was previously conceivable. In Paris, we perform such experiments by juggling with photons trapped between superconducting mirrors. We count these photons in a non-destructive way and we prepare states of the quantum field reminiscent of the famous cat which Schrödinger imagined to be suspended between life and death. I will give a simple description of these studies, compare them to similar ones performed on other systems and guess about possible applications.
The Distinguished Lecturer Series (DLS) follows a colloquium format for a broad audience and will be followed by a reception to provide an opportunity for meeting the speaker.