[10a-Z23-1~8] 4.7 Quantum Optics and Nonlinear Optics

▲ [10a-Z23-2] [INVITED]Emergence of the Geometric Phase from Quantum Measurement Back-action

Young-Wook Cho²、Yosep Kim¹、Yeon-Ho Choi²、Yong-Su Kim²、Sang-Wook Han²、Sang-Yun Lee²、Sung Moon²、〇Yoon-Ho Kim¹ (1.POSTECH、2.KIST)

キーワード：geometric phase, quantum measurement back-action, weak value measurement

The state vector representing a quantum system acquires a phase factor following an adiabatic evolution along a closed trajectory in phase space. This is the traditional example of a geometric phase, or Pancharatnam–Berry phase, a concept that has now been generalized beyond cyclic adiabatic evolutions to include generalized quantum measurements. However, a clear description of the relationship between the emergence of a geometric phase and the effects of a series of generalized quantum measurements on a quantum system has not yet been provided. Here we report that a sequence of weak measurements with continuously variable measurement strengths in a quantum optics experiment conclusively reveals that the quantum measurement back-action is the source of the geometric phase.