Thursday, November 20, 2008, 16:00
WHGA Auditorium
M. DeKieviet, Heidelberg University
Abstract:
The quantum mechanical nature of (empty) space has far-reaching consequences in many
branches of physics, ranging from elementary particles to cosmology. The existence of electromagnetic
vacuum fluctuations, for example, manifests itself most impressively in the Casimir
force. With the current revolution in nano-technology there is a rising need for a quantitative
understanding of this feeble, stochastic force. I will present an experiment, in which the Casimir-
Polder force between a single atom and the surface of a solid is determined quantitatively at
the %-level. In our Atomic Beam Spin Echo Interferometer, we scatter cold 3He atoms from
the attractive part of the atom-surface potential. Since the quantum reflectivity depends very
sensitively on the long-range details of the interaction, we have been able to clearly identify
the Casimir and the van der Waals branches for a variety of systems. The potential of this
experiment is addressed in particular with respect to testing fundamental questions concerning
the Casimir force and beyond, like for example possible deviations from Newton's law of gravity
at the nanometer scale.