Strong coupling in a microcavity containing β-carotene

Area of Science:

• Molecular physics
• Quantum optics
• Biophysics

Background:

• Beta-carotene exhibits distinct electronic and vibronic transitions.
• Microcavities confine light-matter interactions.
• Understanding light-matter coupling is crucial for quantum technologies and biological processes.

Purpose of the Study:

• To fabricate an open-cavity microcavity with beta-carotene.
• To investigate the light-matter coupling regime of beta-carotene transitions within the microcavity.
• To explore potential applications in modifying photosynthetic processes.

Main Methods:

• Fabrication of an open-cavity microcavity structure.
• Thin-film deposition of beta-carotene.
• Spectroscopic analysis of optical absorption and light-matter interactions.
• Modeling transitions using Lorentzian functions.

Main Results:

• Beta-carotene absorption modeled by Lorentzian functions for multiple vibronic transitions (0-0 to 0-4).
• Observed anti-crossing between the cavity mode and the beta-carotene 0-1 vibronic transition.
• Other transitions remained in weak or intermediate coupling due to lower oscillator strength and broader linewidths.

Conclusions:

• Strong light-matter coupling achieved for specific beta-carotene transitions within a microcavity.
• Potential for modifying photosynthetic efficiency and altering molecular energy state ordering.
• Highlights the role of oscillator strength and linewidth in determining coupling regimes.