Unified master equation for molecules in phonon and radiation baths

Area of Science:

• Quantum optics
• Molecular spectroscopy
• Solid-state physics

Background:

• Dissipative mechanisms in impurity molecules are crucial for understanding their quantum behavior.
• Existing theories often rely on approximations like identical potential shapes and the rotating wave approximation.
• Intramolecular vibrational redistributions and non-radiative transitions play significant roles.

Purpose of the Study:

• To develop a unified quantum optical master equation for impurity molecules in crystals.
• To incorporate general vibrational couplings and non-Condon effects.
• To accurately model dissipative relaxation and decoherence mechanisms.

Main Methods:

• Developed a unified quantum optical master equation.
• Relaxed assumptions on potential shapes and the rotating wave approximation.
• Included linear vibrational coupling to phonons and Herzberg-Teller coupling.
• Derived Lamb shifts for all Liouvilleans, including counter-rotating terms.

Main Results:

• The theory successfully reproduces experimental absorption and emission spectra for carbon monoxide.
• New cross terms arising from Condon and non-Condon approximations were identified.
• Demonstrated the model's capability to simulate spectra for nitrogen dioxide, including various relaxation mechanisms.

Conclusions:

• The unified quantum master equation provides a comprehensive framework for studying dissipative processes in polyatomic molecules.
• The developed theory shows promise for applications in molecular quantum memory research.
• Accurate spectral predictions highlight the importance of including non-Condon effects and counter-rotating terms.