||Observation of nonlinear variations in a three-vertex geometric phase in a two-photon polarization qutrit
Ogawa, Kazuhisa ,
Tamate, Shuhei ,
Kobayashi, Hirokazu ,
Nakanishi, ToshihiroKitano, Masao
062118-6 , 2015-06 , American Physical Society
We observed experimentally nonlinear variations in the three-vertex geometric phase in a two-photon polarization qutrit. The three-vertex geometric phase is defined by three quantum states, which generally form a three-state (qutrit) system. By changing one of the three constituent states, we observed two rapid increases in the three-vertex geometric phase. The observed variations are inherent in a three-state system and cannot be observed in a two-state system. We used a time-reversed two-photon interferometer to measure the geometric phase with much more intense signals than those of a typical two-photon interferometer.