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Variational Quantum Eigensolver for Approximate Diagonalization of Downfolded Hamiltonians using Generalized Unitary Coupled Cluster Ansatz

Quantum Physics 2020-11-05 v1 Chemical Physics

Abstract

In this paper we discuss the utilization of Variational Quantum Solver (VQE) and recently introduced Generalized Unitary Coupled Cluster (GUCC) formalism for the diagonalization of downfolded/effective Hamiltonians in active spaces. In addition to effective Hamiltonians defined by the downfolding of a subset of virtual orbitals we also consider their form defined by freezing core orbitals, which enables us to deal with larger systems. We also consider various solvers to identify solutions of the GUCC equations. We use N2_2, H2_2O, and C2_2H4_4, and benchmark systems to illustrate the performance of the combined framework.

Keywords

Cite

@article{arxiv.2011.01985,
  title  = {Variational Quantum Eigensolver for Approximate Diagonalization of Downfolded Hamiltonians using Generalized Unitary Coupled Cluster Ansatz},
  author = {Nicholas P. Bauman and Jaroslav Chládek and Libor Veis and Jiří Pittner and Karol Kowalski},
  journal= {arXiv preprint arXiv:2011.01985},
  year   = {2020}
}
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