- Alexandru Macridin, Fermilab, Chicago, Illinois
Our algorithm extends existing quantum algorithms addressing fermion systems in quantum chemistry and condensed matter physics by including phonons. The phonon degrees of freedom are represented on a truncated Hilbert space with a size that increases linearly with the maximum phonon cutoff number. The additional computational resources required by the presence of phonons scale linearly with the size of the system. We have implemented our algorithm for a Holstein polaron problem on the Argonne 38-qubit ATOS QLM quantum simulator. We find that the polaron energy and phonon number distribution agree very well with exact diagonalization results for the weak, intermediate, and strong electron-phonon coupling regimes.