The Physical Spectrum of a Driven Jaynes-Cummings Model.

Area of Science:

• Quantum optics
• Atomic physics
• Cavity quantum electrodynamics

Background:

• The Jaynes-Cummings model describes light-matter interaction in a cavity.
• Coherent driving introduces external classical fields to the system.
• Understanding spectral response is crucial for quantum technologies.

Purpose of the Study:

• To analyze the time-dependent physical spectrum of a driven Jaynes-Cummings model.
• To derive closed-form expressions for atomic and field operator correlation functions.
• To investigate the impact of coherent driving on spectral properties.

Main Methods:

• Unitary transformations to map the time-dependent Hamiltonian to a stationary form.
• Derivation of closed-form expressions for two-time correlation functions.
• Evaluation of the time-dependent physical spectrum using the Eberly-Wódkiewicz definition.

Main Results:

• External driving causes significant modifications in atomic spectral response, including frequency shifts and asymmetric line shapes.
• A specific driving regime was identified where the cavity field's coherent displacement cancels the initial coherent amplitude.
• In this regime, the system dynamics mimic a vacuum-initialized Jaynes-Cummings model, recovering vacuum Rabi splitting.

Conclusions:

• Coherent driving offers control over spectral features in the Jaynes-Cummings model.
• The observed spectral features are attributed to coherent field displacement, not altered atom-cavity coupling.
• This work provides insights into controlling and interpreting quantum system dynamics under external driving.