Rempe is considered a pioneer of the field of
cavity quantum electrodynamics. He was first to observe how a single atom repeatedly emits and absorbs a single photon. First experiments he performed with microwave photons in superconducting cavities. Later he expanded his interest to optical photons between mirrors of highest possible reflectivity. His experiments laid the foundation for the development of quantum nonlinear optics, in which a single particle, be it an atom or a photon, causes an effect that many particles cannot induce. Rempe has used his findings from basic research to develop novel interfaces between light and matter. These interfaces connect the everyday world with the quantum world and have potential applications as senders, receivers and memories of information in a future global quantum network. A remarkable feature of the interface is its ability to detect single photons nondestructively, which opens new perspectives for a scalable quantum computer. The interface is also suitable to observe and control the motion of a single atom in real time, as well as to generate quantum light with noise below the shot noise level. Rempe has also done pioneering work in the field of atom optics and quantum gases. By means of an atom interferometer he was able to demonstrate experimentally that for an observed object passing through a double-slit arrangement quantum mechanical wave-particle duality is based on entanglement, instead of Heisenberg's uncertainty relation for position and momentum, as often stated in textbooks. He has produced the first Bose-Einstein condensate outside the U.S. and has used it to generate, among others, a strongly correlated gas of molecules by means of the quantum Zeno effect. In a third research focus Rempe follows the goal to produce an ultracold gas of polyatomic molecules. The focus lies on the development of novel methods for slowing down complex molecules using a centrifuge and for cooling such molecules using the Sisyphus effect. The aim is to understand chemical reactions at low temperatures, to open new reaction channels, to prepare molecules for precision experiments, as well as producing neutral quantum many-body systems with a long-range electrical interaction. In addition to his research and teaching activities, Rempe was and is engaged in academic self-administration, such as speaker of the Quantum Optics and Photonics section of the German Physical Society, the curator of several magazines such as "Physics in our Time", "Journal of Optics" and "Optics Communications", as chairperson of a selection panel of the European Research Council, as managing director of the Max Planck Institute of Quantum Optics and chairperson of the prize committee of the Stern-Gerlach medal of the German Physical Society. == References ==