Violation of Leggett-Garg Inequality in an Atomic Ensemble
Chang-Hau Kuo1*, Chih-Sung Chuu1
1Department of Physics, National Tsing Hau University, Hsinchu, Taiwan
* presenting author:郭昌昊,
Study of quantum behavior in a macroscopic object has been a long-standing interest to physicists since Schrodinger’s seminal example of entangled “cat” state. We study the highly-entangled state in a cigar-like atomic ensemble created by a single photon excitation, and discuss how its quantum properties, as distributed throughout a macroscopic scale, preserve over time. We find that the dynamics of the atomic ensemble behaves like a two-level-emitter in an optical cavity on resonance. We also discuss the quantum nature of these oscillations by testing the validity of extended Leggett-Garg inequality as the system evolves in time.

Keywords: Leggett-Garg inequality