Related Experiment Videos
Quantitative study of amplitude noise effects on dynamical localization
1Department of Physics, The University of Texas at Austin, Austin, Texas 78712-1081, USA.
Summary
We investigated how noise affects cold atoms in a pulsed light field, a quantum kicked rotor model. Introducing noise destroys quantum localization, restoring classical diffusion and leading to a quantum-to-classical transition.
Area of Science:
- Atomic physics
- Quantum dynamics
- Nonlinear dynamics
Background:
- The quantum kicked rotor is a model system for studying quantum chaos.
- Dynamical localization in quantum systems suppresses classical diffusion.
- Amplitude noise can disrupt quantum coherences.
Purpose of the Study:
- To experimentally investigate the effect of amplitude noise on the quantum kicked rotor.
- To study the transition from quantum dynamical localization to classical diffusion.
- To explore noise-induced restoration of classical behavior in a quantum system.
Main Methods:
- Experimental realization of the quantum kicked rotor using cold atoms in a pulsed standing wave of light.
- Introduction of controlled amplitude noise into the light field.
- Measurement of atomic momentum distribution to observe diffusion and localization.
Main Results:
- Dynamical localization was observed in the absence of noise, suppressing momentum diffusion.
- Introduction of amplitude noise destroyed the coherences responsible for localization.
- Restored classical diffusion was observed with increasing noise levels.
- High noise levels led to experimental results well-described by a classical model.
Conclusions:
- Amplitude noise can induce a transition from quantum to classical behavior in the quantum kicked rotor.
- Quantum effects like dynamical localization are fragile and sensitive to noise.
- The study provides experimental evidence for noise-induced classicality in a quantum chaotic system.