Multiset Variational Quantum Dynamics Algorithm for Simulating Nonadiabatic Dynamics on Quantum Computers

Accelerating quantum dynamical simulations with quantum computing has received considerable attention but remains a significant challenge. In variational quantum algorithms for quantum dynamics, designing an expressive and shallow-depth parametrized quantum circuit (PQC) is a key difficulty. Here, we propose a multiset variational quantum dynamics algorithm (MS-VQD) tailored for nonadiabatic dynamics involving multiple electronic states. The MS-VQD employs multiple PQCs to represent the electronic–nuclear coupled wave function, with each circuit adapting to the motion of the nuclear wavepacket on a specific potential energy surface. By simulating excitation energy transfer dynamics in molecular aggregates described by the Frenkel–Holstein model, we demonstrate that the MS-VQD achieves the same accuracy as the traditional VQD while requiring significantly shallower PQCs. Notably, its advantage increases with the number of electronic states, making it suitable for simulating nonadiabatic quantum dynamics in complex molecular systems.