Inaugural lecture and reception: Klaus Mølmer

From quantum optics to bits and pieces

In this talk, I shall give a personally flavored account of the development of quantum optics. I will do this by sharing how I was totally overwhelmed and changed the topic of my PhD study immediately after reading the simple, yet stunning, arguments applied by Roy Glauber to characterize temporal fluctuations in photo-detection signals.  Such fluctuations can be signatures of non-classical properties, and the theory of photo-detection fueled the field of quantum optics with visions to prepare and apply a variety of quantum states of light and atomic light emitters in experiments. In the past decades, bits and pieces of solid-state materials were manufactured with high purity and precision, enabling observation of similar phenomena as we study with single atoms and photons in quantum optics. 

As a theorist I have worked with methods to describe the dynamics of open quantum systems, i.e., systems subject to interactions with their environment. I will show how these methods reintroduce, but with a plot twist, Niels Bohr’s quantum jumps in modern quantum physics. They also refine and elaborate on Glauber’s theories and while the original intent was to develop efficient theoretical and numerical methods that we can apply to quantum optics and solid-state bits and pieces, the same methods offer unique insights in physical dynamics and delightful encounters with the famous discussions between Niels Bohr and Albert Einstein on the interpretation of quantum theory.