  Current precision experiments with single (anti)protons to test CPT symmetry
progress at a rapid pace, but are complicated by the need to cool particles to
sub-thermal energies. We describe a cryogenic Penning-trap setup for $^9$Be$^+$
ions designed to allow coupling of single (anti)protons to laser-cooled atomic
ions for sympathetic cooling and quantum logic spectroscopy. We report on
trapping and laser cooling of clouds and single $^9$Be$^+$ ions. We discuss
prospects for a microfabricated trap to allow coupling of single (anti)protons
to laser-cooled $^9$Be$^+$ ions for sympathetic laser cooling to sub-mK
temperatures on ms time scales.
