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arXiv · 2104.06428

Simulating a ring-like Hubbard system with a quantum computer

Philippe Suchsland·Panagiotis Kl. Barkoutsos·Ivano Tavernelli·Mark H. Fischer·Titus Neupert
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Abstract

We develop a workflow to use current quantum computing hardware for solving quantum many-body problems, using the example of the fermionic Hubbard model. Concretely, we study a four-site Hubbard ring that exhibits a transition from a product state to an intrinsically interacting ground state as hopping amplitudes are changed. We locate this transition and solve for the ground state energy with high quantitative accuracy using a variational quantum algorithm executed on an IBM quantum computer. Our results are enabled by a variational ansatz that takes full advantage of the maximal set of commuting $\mathbb{Z}_2$ symmetries of the problem and a Lanczos-inspired error mitigation algorithm. They are a benchmark on the way to exploiting near term quantum simulators for quantum many-body problems.

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Philippe Suchsland, Panagiotis Kl. Barkoutsos, Ivano Tavernelli, Mark H. Fischer, Titus Neupert. 2021-04-13. Simulating a ring-like Hubbard system with a quantum computer. https://doi.org/10.1103/physrevresearch.4.013165

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