AGP-based unitary coupled cluster theory for quantum computers

• URL: http://arxiv.org/abs/2205.13420v2
• Date: Fri, 23 Sep 2022 02:04:54 GMT
• Title: AGP-based unitary coupled cluster theory for quantum computers
• Authors: Armin Khamoshi, Guo P. Chen, Francesco A. Evangelista, Gustavo E. Scuseria
• Abstract summary: We develop a unitary coupled cluster method on the antisymmetrized geminal power (AGP) We demonstrate our method for the single-band Fermi--Hubbard Hamiltonian in one and two dimensions.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Electronic structure methods typically benefit from symmetry breaking and restoration, specially in the strong correlation regime. The same goes for Ans\"atze on a quantum computer. We develop a unitary coupled cluster method on the antisymmetrized geminal power (AGP) -- a state formally equivalent to the number-projected Bardeen--Cooper--Schrieffer wavefunction. We demonstrate our method for the single-band Fermi--Hubbard Hamiltonian in one and two dimensions. We also explore post-selection as a state preparation step to obtain correlated AGP and prove that it scales no worse than $\mathcal{O}(\sqrt{M})$ in the number of measurements, thereby making it a less expensive alternative to gauge integration to restore particle number symmetry.

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