Return to the Origin as a Probe of Atomic Phase Coherence

Area of Science:

• Quantum physics
• Atomic physics
• Cold atom experiments

Background:

• Quantum interference phenomena, such as weak localization, are crucial for understanding particle behavior in complex systems.
• The "enhanced return to the origin" (ERO) is a specific manifestation of quantum interference observed in wave packet dynamics.

Purpose of the Study:

• To observe and characterize the coherent enhancement of the return to the origin (ERO) in a cold atom gas.
• To investigate the temporal dynamics of ERO and its dependence on periodic perturbations.
• To utilize the quantum-coherent nature of ERO for quantifying decoherence rates in atomic systems.

Main Methods:

• Subjecting a cold atom gas to a pulsed, periodically shifted laser standing wave.
• Inducing and observing oscillations in the ERO probability over time.
• Monitoring the temporal decay of ERO to analyze system decoherence.

Main Results:

• Observation of coherent enhancement of the return probability (ERO) in a periodically kicked cold-atom gas.
• Demonstration of time-oscillating ERO, explained by periodic, reversible dephasing in weak-localization interference.
• Successful quantification of the atomic system's decoherence rate by exploiting the quantum-coherent nature of ERO.

Conclusions:

• The study confirms the coherent nature of ERO in periodically perturbed cold atom systems.
• Periodic dephasing dynamics directly influence the observed ERO oscillations.
• ERO serves as a sensitive probe for measuring decoherence in quantum atomic systems.