Lene Vestergaard Hau (; born November 13, 1959) is a Danish physicist and educator. She is the Mallinckrodt Professor of Physics and of Applied Physics at Harvard University. In 1999, she led a Harvard University team who, by use of a Bose–Einstein condensate, succeeded in slowing a beam of light to about 17 metres per second, and, in 2001, was able to stop a beam completely. Later work based on these experiments led to the transfer of light to matter, then from matter back into light, a process with important implications for quantum encryption and quantum computing. More recent work has involved research into novel interactions between ultracold atoms and nanoscopic-scale systems. In addition to teaching physics and applied physics, she has taught Energy Science at Harvard, involving photovoltaic cells, nuclear power, batteries, and photosynthesis. In addition to her own experiments and research, she is often invited to speak at international conferences, and is involved in structuring the science policies of various institutions. She was keynote speaker at EliteForsk-konferencen 2013 ("Elite Research Conference") in Copenhagen, which was attended by government ministers, as well as senior science policy and research developers in Denmark. In acknowledgment of her many achievements, Discover Magazine recognized her in 2002 as one of the 50 most important women in science. Early life, family and education Hau was born in Vejle, Denmark. Hau earned her bachelor's degree in Mathematics in 1984 at the University of Aarhus in Denmark at the age of 24. Hau continued her studies there, receiving her master's degree in Physics two years later. For her doctoral studies in quantum theory, Hau worked on ideas similar to those involved in fibre optic cables carrying light, but her work involved strings of atoms in a silicon crystal carrying electrons. While working towards her doctorate, Hau spent seven months at CERN, the European Laboratory for Particle Physics near Geneva. She received her doctorate from the University of Aarhus in 1991 at the age of 32, but by this time her research interests had changed direction. Career In 1991 she joined the Rowland Institute for Science at Cambridge, Massachusetts as a scientific staff member, beginning to explore the possibilities of slow light and cold atoms. In 1999 at the age of 40, Hau accepted a two-year appointment as a postdoctoral fellow at Harvard University. Her formalized training is in theoretical physics but her interest moved to experimental