Presented by Brian Odom:
"Towards Precision Spectroscopy of Single Trapped Molecular Ions"
Precision of the best molecular spectroscopy is currently orders of magnitude behind atomic ion spectroscopy, owing primarily to challenges in molecular state preparation and readout. Applications of improved molecular spectroscopy would include searches for time-variation of fundamental constants, parity violation studies, and searches for fundamental electric dipole moments. Our group at Northwestern University is developing the necessary tools to perform clock-quality spectroscopy on single trapped molecular ions. Primarily because of the diagonal Franck-Condon factors in the B-X transition, we have chosen to work with SiO+ molecular ions, which we have successfully loaded into a linear Paul trap by laser ablation. Optical pumping into the ground state will be achieved by optical pulse filtering, for which we have demonstrated the necessary resolution at the B-X transition wavelength. Although we plan to use co-trapped Ba+ ions for SiO+ sympathetic cooling and state readout, I will briefly discuss our modeling of direct Doppler cooling of SiO+. Finally, I will discuss our progress on single-ion Ba+ spectroscopy in a second trap designed for the SiO+ rovibrational spectroscopy experiment.
Presented by Erik Lenferink:
"Collective Single Molecule Magnet Dynamics: Incoherent Landau-Zener Tunneling"
Single Molecule Magnets (SMMs) are a class of nanoscale magnets consisting of organic compounds and magnetic ions. The total spin of SMMs has been observed to tunnel purely in a quantum mechanical fashion at low temperatures, which can be explained via a theoretical analysis of the SMM Hamiltonian. Results of incoherent tunneling of spin for SMMs will be presented from Monte Carlo simulations as well as numeric solutions of kinetic equations for the evolution of the SMM energy distribution function.
February 29, 2012. 12:00pm
Room F235, Technological Institute
