Speaker: Michael Drewsen Aarhus University
Time: 2013-08-13 10:00-2013-08-13 11:00
Trapped and laser cooled atomic ions in the form of Coulomb crystals represent interesting objects for investigations of Cavity Quntum ElectroDynamics (CQED) and related phenomena. First of all, the number and density of atoms in such crystals as well as the shapes of the crystals can relatively easily be controlled. Second, the ion-ion Coulomb repulsion results in an essentially collision-free environment with the prospect of long coherence times. These properties were recently exploited in experiments focused on investigations of the collective coupling of cold ion ensembles to light modes of a Fabry-Perot cavity , as well as in demonstration of cavity Electromagnetically Induced Transparency (EIT) and a photon blockade mechanism . The next step of these experiments will be to realize a light storage scheme, partly for demonstrating an efficient photoncounting device  and partly for eventually establishing a quantum memory for light with both high efficiency and fidelity . Further enhancement of the coupling strengths between the ions and the cavity field will be pursued by applying optical dipole potentials [5,6].
 Herskind P. F., Dantan A., Marler J. P., Albert M., and Drewsen M., “Realization of
collective strong coupling with ion Coulomb crystals in an optical cavity, Nat. Phys. 5,
 Albert, M., Dantan, A. and Drewsen, M., "Cavity electromagnetically induced
transparency and all-optical switching using ion Coulomb crystals", Nat. Phot. 5, 633
 Clausen, C., Sangouard, N. and Drewsen, M., “Analysis of a photon number resolving
detector based on an ion coulomb crystal inside an optical cavity”, New J.
 Zangenberg K. R., Dantan A., Drewsen M.,”Spatial mode effects in a cavity EIT-based
quantum memory with ion Coulomb crystals”, J. Phys. B 45, 124011 (2012).
 Linnet R. B., Leroux I. D., Marciante M., Dantan A., and Drewsen M., “Pinning an Ion
with an Intracavity Optical Lattice”, Phys. Rev. Lett. 109, 233005 (2012).
 Horak P., Dantan A.,and Drewsen M., “Optically induced structural phase transitions in
ion Coulomb crystals”, Phys. Rev. A. 86, 043435 (2012).
M. Drewsen is 48 year old. He obtained his PhD in Physics from the Aarhus University in 1994. Hereafter, he had a postdoctoral position in the group of Prof. J. Mlynek, Universität Konstanz, Germany, for nearly two years. In August 1995, he returned to Aarhus University, where he first held an assistant professorship (1995-2001), then an associated professorship (2001-2009), and most recently a full professorship (2009-).
Drewsen has pioneering research based on cold molecular ions embedded in Coulomb crystals, as well made several seminal contributions to the studies of Coulomb crystals and their applications within quantum optics.
Drewsen has since 2006 been the branch-leader at AU of the quantum optics center QUANTOP funded by the Danish National Research Foundation, and have served as local node-leader for six EU networks, as member of various international boards and panels.
Over the past 10 years, Drewsen has delivered more than 50 invited talks at international meetings, as well as about 30 presentations at universities and research institutions.
Currently, the Ion Trap Group led by Drewsen includes 3 postdocs and 3 PhD students, and 3 master students.
Scientific Expertise: Drewsen’s expertise includes cold molecular ions research with particular focus on development and exploration of techniques suitable for single molecule investigations. In addition, based on several seminal contributions to the studies of Coulomb crystals, Drewsen has become a capacity in exploiting such crystal within the field of cavity QED and quantum information science.