Hybrid Quantum-Classical Boson Sampling Algorithm for Molecular Vibrationally Resolved Electronic Spectroscopy with...

Area of Science:

• Quantum computing
• Computational chemistry
• Spectroscopy

Background:

• Boson sampling on photonic quantum computers shows significant advantages over classical methods.
• Developing quantum algorithms for practical scientific problems like molecular spectroscopy is crucial.
• Classical sum-over-states methods for optical spectra suffer from exponential computational complexity with system size.

Purpose of the Study:

• To propose a novel hybrid quantum-classical sampling (HQCS) algorithm.
• To accurately calculate optical spectra for complex molecules, including Duschinsky rotation and anharmonicity.
• To overcome the computational limitations of classical methods.

Main Methods:

• The HQCS algorithm employs an intermediate harmonic potential energy surface (PES) to connect initial and final PESs.
• Boson sampling and classical algorithms estimate the overlap magnitude and sign between initial and intermediate states.
• Classical algorithms efficiently evaluate the overlap between intermediate and final states.

Main Results:

• The feasibility of the HQCS algorithm was demonstrated.
• Accurate calculations of emission spectra were performed for a Morse model and the pyridine molecule.
• The hybrid approach shows promise for complex molecular systems.

Conclusions:

• The HQCS algorithm provides an efficient and feasible method for calculating molecular optical spectra.
• This hybrid approach effectively incorporates Duschinsky rotation and anharmonicity.
• The study highlights the potential of quantum computing for advancing computational chemistry.