2025-05-23 パシフィック・ノースウェスト国立研究所(PNNL)
<関連情報>
- https://www.pnnl.gov/publications/unleashing-quantum-computing-quantum-chemistry-constrained-optimization
- https://www.nature.com/articles/s41534-024-00916-8
制約条件付き最適化から解き放たれた量子化学のための量子コンピューティング:ジェネレーター座標に触発された方法を用いて Unleashed from constrained optimization: quantum computing for quantum chemistry employing generator coordinate inspired method
Muqing Zheng,Bo Peng,Ang Li,Xiu Yang & Karol Kowalski
npj Quantum Information Published0:3 December 2024
DOI:https://doi.org/10.1038/s41534-024-00916-8
Abstract
Hybrid quantum-classical approaches offer potential solutions to quantum chemistry problems, yet they often manifest as constrained optimization problems. Here, we explore the interconnection between constrained optimization and generalized eigenvalue problems through the Unitary Coupled Cluster (UCC) excitation generators. Inspired by the generator coordinate method, we employ these UCC excitation generators to construct non-orthogonal, overcomplete many-body bases, projecting the system Hamiltonian into an effective Hamiltonian, which bypasses issues such as barren plateaus that heuristic numerical minimizers often encountered in standard variational quantum eigensolver (VQE). Diverging from conventional quantum subspace expansion methods, we introduce an adaptive scheme that robustly constructs the many-body basis sets from a pool of the UCC excitation generators. This scheme supports the development of a hierarchical ADAPT quantum-classical strategy, enabling a balanced interplay between subspace expansion and ansatz optimization to address complex, strongly correlated quantum chemical systems cost-effectively, setting the stage for more advanced quantum simulations in chemistry.