Fluctuations and Decoherence in Chaos-Assisted Tunneling

Author :Daniel A. Steck, Windell H. Oskay, and Mark G. Raizen
Publication :Physical Review Letters
Volume :88
Number :12
Pages :120406
Year :2002

We study quantum dynamical tunneling between two symmetry-related islands of stability in the phase
space of a classically chaotic system. The setting for these experiments is the motion of carefully
prepared samples of cesium atoms in an amplitude-modulated standing wave of light. We examine the
dependence of the tunneling dynamics on the system parameters and indicate how the observed features
provide evidence for chaos-assisted (three-state) tunneling. We also observe the influence of a noisy
perturbation of the standing-wave intensity, which destroys the tunneling oscillations, and we show that
the tunneling is more sensitive to the noise for a smaller value of the effective Planck constant.