Item

Abstract

This thesis is the realization of the long standing goal of sympathetically cooling
single particles with image currents. Particles with no electronic structure such as
the bare proton or antiproton, are not amenable to standard laser cooling and manipulation
techniques and until now have been cooled only by coupling to cryogenic
tank circuits. In measurements of the proton and antiproton g-factor however, the
energy splitting used to read out the particle's spin state is larger than thermal energy
fluctuations and special techniques are required to perform the measurement.
The technique developed here uses a cloud of laser cooled beryllium ions to sympathetically
cool a single proton by coupling to, and cooling a mode of the tank
circuit. The use of this circuit resonantly enhances the energy exchange between
the trapped particles and allows the cooling ions to be separated from the particle
of interest over arbitrary distances. This technique, is the first demonstration of
sympathetic cooling of a proton and a macroscopic LC circuit to below 25% of the
environment temperature.
Sympathetically cooled protons and antiprotons with this method enable an improved
g-factor measurement by increasing the duty cycle of the experiment. This
will further our understanding of matter-antimatter asymmetry by constraining
CPT odd new physics and enhancing sensitivity to even more exotic physics. Moreover,
the technique presented here has general applications in experiments with
trapped charged particles, enabling coupling of a large number of ions, distributed
in many separated trapping regions to a single cold resonator.