We investigate the quantum computing of the vibrational dynamics of CO2 and H2O by constructing the vibrational Hamiltonian in qubit and qudit form by two types of qubit encodings (binary and direct) and a qudit encoding. We simulate the time-dependent vibrational population transfer using the three different encodings, including the effect of noise and find that the qudit encoding leads to the most accurate results both for CO2 and H2O because of the small number of terms in the qudit Hamiltonian as long as the same values of the entangling gate error rates are adopted.
@article{arxiv.2605.12866,
title = {Simulation of vibrational dynamics using qubits and qudits},
author = {Erik Lötstedt and Kaoru Yamanouchi},
journal= {arXiv preprint arXiv:2605.12866},
year = {2026}
}