Quest-Talk: Christian Schmiegelow, Departamento de Física - Universidad de Buenos Aires

Donnerstag, 20.09.2012, 11:00 h Paschen-Bau

Light with orbital angular momentum interacting with trapped ions

Light beams carrying angular momentum can interact with a single,
trapped and well localized ion. In such case the dependencies on the
angular momentum and polarization of the laser beam as well as the
direction of the quantization magnetic field define special
selection rules. In order to optimally observe the specific effects,
focusing the angular momentum beam close to the diffraction limit is
required. Various applications and advantages are expected when
using light carrying angular momentum: In quantum information
processing, where qubit states of ion crystals are controlled,
parasitic light shifts could be avoided as the ion is excited in the
dark zone of the beam at zero electric field amplitude. In
spectroscopy one might access transitions which have escaped
excitation so far due to vanishing transition dipole moments.