Poul S. Jessen is a Professor of Optical Science and Chair of Quantum Information and Control in the College of Optics at the University of Arizona in the USA. He received his Bachelors and Masters degrees in Chemistry and Physics from the University of Aarhus in 1987 and 1989, respectively. As a PhD student he joined the group of Dr. William D. Phillips at the US National Institute of Standards and Technology where he worked on the first experiment to observe quantized atomic motion in Optical Lattices. For this research he was awarded his PhD in Physics from the University of Aarhus in 1993. Jessen was appointed as a tenure track assistant professor at the Optical Sciences Center (now College of Optical Sciences) at the University of Arizona in 1993. He is a fellow of the American Physical Society, and a founding member of the Center for Quantum Information and Control. His research interests lie at the intersection of experimental atomic physics, quantum optics, and quantum information science. Recent and current projects include quantum control and measurement of single and collective atomic spins, quantum control of atoms in optical lattices, light-matter quantum interfaces based on atoms in optical nanofiber traps, spin squeezing and its use in quantum metrology, quantum tomography, quantum chaos, and quantum simulation.