Markus Arndt is a Professor of Physics at the University of Vienna and head of the Quantum Nanophysics Group. After his Ph.D. with Antoine Weis and Theodor W. Hänsch at MPQ Garching and LMU Munich he spent two years with Jean Dalibard at the ENS Paris where he worked on ultracold atoms, atom optics, and atom interferometry. In 1997 he joined Anton Zeilinger as a postdoc in Innsbruck to jointly start the field of macromolecule interferometry. He moved to Vienna in 1999 where he has worked ever since. His current interests cover matter-wave interferometry, molecular quantum optics, quantum-enhanced molecule metrology, molecular sources, detectors, and cooling methods as well as the interface between quantum physics and biology.