Communications Physics

A hybrid quantum-classical method for electron-phonon systems

M. Michael Denner, Alexander Miessen, Haoran Yan, Ivano Tavernelli, Titus Neupert, Eugene Demler, Yao Wang

Published Aug 28, 2023• 9 citations

Abstract

Abstract Interactions between electrons and phonons play a crucial role in quantum materials. Yet, there is no universal method that would simultaneously accurately account for strong electron-phonon interactions and electronic correlations. By combining methods of the variational quantum eigensolver and the variational non-Gaussian solver, we develop a hybrid quantum-classical algorithm suitable for this type of correlated systems. This hybrid method tackles systems with arbitrarily strong electron-phonon coupling without increasing the number of required qubits and quantum gates, as compared to purely electronic models. We benchmark our method by applying it to the paradigmatic Hubbard-Holstein model at half filling, and show that it correctly captures the competition between charge density wave and antiferromagnetic phases, quantitatively consistent with exact diagonalization.

DOI: 10.1038/s42005-023-01353-3

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