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Variational Quantum Annealing for Quantum Chemistry

Quantum Physics 2025-03-20 v1 Chemical Physics

Abstract

We introduce a variational quantum annealing (VarQA) algorithm for electronic structure theory, in which we use the quantum annealer as a sampler and prepare an ansatz state through its statistics. We also introduce a strategy called the "digitizer" for searching the space of variational parameters efficiently. We demonstrate the effectiveness of VarQA by evaluating the ground-state potential energy surface for molecules with up to 2020 spin orbitals as well as an excited-state potential energy surface. This approach resembles the workings of the quantum Boltzmann Machines (QBMs), but is generalized to handle distributions beyond the Boltzmann distribution. In VarQA, with the number of required logical qubits equal to the number of spin orbitals, a fully connected Ising Hamiltonian can be readily implemented in a large-scale quantum annealer as a scalable ansatz for electronic structure calculations.

Keywords

Cite

@article{arxiv.2503.15473,
  title  = {Variational Quantum Annealing for Quantum Chemistry},
  author = {Ka-Wa Yip and Kübra Yeter-Aydeniz and Sijia S. Dong},
  journal= {arXiv preprint arXiv:2503.15473},
  year   = {2025}
}
R2 v1 2026-06-28T22:27:15.301Z