Dynamical approach to complementarity of interferometers

Abstract

The complementarity for wave-like and particle-like properties of a quantum mechanical particle in the Mach–Zehnder interferometer is investigated by means of the dynamical approach. Measurement devices are placed on the paths of the interferometer to obtain the information of a propagating particle. The which-path information of the particle and the fringe visibility of the interferometer are derived by considering the dynamics of the particle and devices. When each device consists of a single qubit, the maximum amount of the which-path information is obtained and the complementary relation is examined.

Keywords:

• complementarity
• visibility
• which-path information
• dynamical approach

Acknowledgements

The author would greatly appreciate Profs F. Shibata and S. Kitajima of Ochanomizu University for their useful comments and encouragement.