Introduction

What happens when antimatter and matter meet? (annihilate, repel, bind, or breakup) is a fascinating question. Antimatter ultimately pair annihilate. For example, the positron (the antiparticle of the electron) is converted into gamma rays, while antiprotons and antineutrons are converted into fast pions. It might not be so interesting if it annihilates, but rather the physical processes leading up to annihilation are often considered to be of greater importance. There are various forms of matter containing antiparticles, or antiatoms, one of which is the positronium atom. This is a two body binding system of an electron and a positron, analogous to the hydrogen atom. We focus on studying how positronium atoms interact with matter. We also study the control of atomic quantum states using periodic magnetic materials and its applications.