Cho, Young-Wook Kim, Yosep Choi, Yeon-Ho Kim, Yong-Su Han, Sang-Wook Lee, Sang-Yun Moon, Sung Kim, Yoon-Ho 2024-01-19T19:34:20Z 2024-01-19T19:34:20Z 2021-09-02 2019-07 1745-2473 https://pubs.kist.re.kr/handle/201004/119834 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, and that has been experimentally measured in a variety of physical systems. 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-that is, the stronger a quantum measurement, the larger the accumulated geometric phase. We furthermore find that in the limit of strong (projective) measurement there is a direct connection between the geometric phase and the sequential weak value, ordinarily associated with a series of weak quantum measurements. English NATURE PUBLISHING GROUP BERRY PHASE SPIN Emergence of the geometric phase from quantum measurement back-action Article 10.1038/s41567-019-0482-z 1 NATURE PHYSICS, v.15, no.7, pp.665 - + NATURE PHYSICS 15 7 665 + scie scopus 000473331000020 2-s2.0-85064563977 Physics, Multidisciplinary Physics Article BERRY PHASE SPIN