Quantum-Electrodynamical Time-Dependent Density Functional Theory Description of Molecules in Optical Cavities

Area of Science:

• Quantum chemistry
• Computational physics
• Molecular modeling

Background:

• Accurately modeling light-matter interactions is crucial for understanding molecular behavior in confined environments.
• Existing methods often face computational limitations when simulating strong coupling between molecules and quantized fields.

Purpose of the Study:

• To introduce a novel computational framework, quantum-electrodynamical time-dependent density functional theory with a tensor-product representation (QED-TDDFT-TP).
• To enable accurate and scalable simulations of molecules strongly coupled to quantized cavity fields.

Main Methods:

• Combining real-space electronic wave functions with truncated Fock-space photon states.
• Utilizing a tensor-product representation for efficient computation.
• Comparing results with high-level quantum electrodynamics methods (QED-FCI, QED-CASCI).

Main Results:

• QED-TDDFT-TP demonstrates good agreement with benchmark calculations for ground-state energies and polaritonic spectra.
• Cavity confinement significantly alters binding energies and geometries of weakly bound dimers.
• Polarization-dependent effects of cavity confinement on molecular structure were observed.

Conclusions:

• QED-TDDFT-TP offers a computationally efficient and accurate tool for studying cavity quantum electrodynamics.
• The framework advances the understanding of how quantized fields modify molecular structure and interactions.
• This method opens new avenues for designing materials and understanding chemical processes in optical cavities.