Decoherence and Momentum Relaxation in Fermi-Polaron Rabi Dynamics: A Kinetic Equation Approach

Area of Science:

• Quantum Many-Body Physics
• Ultracold Atomic Gases
• Quantum Kinetic Theory

Background:

• The Fermi-polaron model is crucial for understanding interacting quantum systems.
• Describing the nonlinear dynamics of Fermi-polarons theoretically remains challenging.
• Recent experiments with ultracold atoms probe Rabi oscillations of Fermi-polarons.

Purpose of the Study:

• To theoretically describe the nonlinear dynamics of driven Fermi-polarons.
• To apply quantum kinetic theory to recent ultracold atom experiments.
• To investigate decoherence and momentum relaxation in strongly interacting Fermi gases.

Main Methods:

• Application of a quantum kinetic theory for driven polarons.
• Analysis of Rabi oscillations between Fermi-polaron and noninteracting states.
• Separation of decoherence and momentum relaxation processes.

Main Results:

• The theory accurately predicts experimental data for Fermi-polaron dynamics without fitting parameters.
• Decoherence and momentum relaxation rates exhibit distinct dependencies on microscopic processes.
• Both the polaron ground state and excited repulsive-polaron states are described.

Conclusions:

• The quantum kinetic theory provides a robust framework for driven polarons.
• The approach successfully models ultracold atom experiments involving Rabi oscillations.
• It offers insights into decoherence and collisional effects in imbalanced Fermi gases.