Geometric Phase of Three-Level Systems in Interferometry
Barry Cyril Sanders, Hubert de Guise, Stephen D. Bartlett, Weiping Zhang · Physical Review Letters · 2001
We present the first scheme for producing and measuring an Abelian geometric phase shift in a three-level system where states are invariant under a non-Abelian group. In contrast to existing experiments and proposals for experiments, based on U(1)-invariant states, our scheme geodesically evolves U(2)-invariant states in a four-dimensional SU(3)/U(2) space and is physically realized via a three-channel optical interferometer.