Cooling to absolute zero
PhD defence, Friday 10 February 2012. Gregers Poulsen.
2012.02.07 |
Gregers Poulsen
Most scientific theories are based on natural constants, but a topical question is whether these actually are constant, or whether they possibly vary temporally or spatially.
This can be investigated by constantly measuring the absorption of light by different atoms. Great measuring precision is required to detect any variations – the wavelength of the light must typically be determined within 0.000 000 000 001%. To achieve such precision, the atoms need to be cooled down to extremely low temperatures. In his PhD studies, Gregers Poulsen worked on achieving this cooling, and he recently demonstrated cooling to a temperature of just 0.000 007˚C above absolute zero.
The PhD degree was completed at the Department of Physics and Astronomy, Science and Technology, Aarhus University.
Time: Friday 10 February 2012 at 14.00
Place: Physics Lecture Theatre, building 1523
Title of dissertation: Sideband Cooling of Atomic and Molecular Ions
Contact information: Gregers Poulsen, ggp@phys.au.dk, +45 8715 5671
Members of the assessment committee:
Professor Piet O. Schmidt, National Metrology Institute (PTB), Braunschweig, Germany
Professor Patrick Gill, National Physical Laboratory (NPL), Middlesex, UK
Professor Arne Nylandsted Larsen (chair), Department of Physics and Astronomy, Aarhus University
Main supervisor:
Professor Michael Drewsen, Department of Physics and Astronomy, Aarhus University
Language: The dissertation will be defended in English
The defence is public.
The dissertation is available for reading at the Graduate School of Science and Technology / GSST, Ny Munkegade 120, building 1521, room 112, 8000 Aarhus C.
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