Correction scheme for molecular total energies from quantum phase estimation under limited qubit resources

Abstract

We propose a practical method for accurately evaluating molecular total energies using a hybrid approach that integrates fault-tolerant quantum computers with classical computing. Our scheme consists of two complementary components: quantum dominant orbital selection (QDOS) and subspace dynamical correlation (SDC). QDOS extracts only the essential active orbitals from the complete active space (CAS) configuration interaction (CI) state on a quantum computer, yielding a compact active space suitable for classical CASCI calculations. SDC then evaluates dynamical-correlation corrections for the CASCI energy using this compact state, which remains tractable on classical machines. To demonstrate that the CAS energy obtained on a quantum computer can be post-corrected by SDC, we examine two frameworks: multireference perturbation theory and tailored coupled-cluster theory. Our scheme enables effective treatment of relatively large molecular systems by combining limited quantum and classical resources.

References in corpus (15)

• Quantum Computing in the NISQ era and beyond
• A variational eigenvalue solver on a quantum processor
• Simulated Quantum Computation of Molecular Energies
• Recent developments in the PySCF program package
• Logical quantum processor based on reconfigurable atom arrays
• Hybrid Quantum-Classical Hierarchy for Mitigation of Decoherence and Determination of Excited States
• Automated Selection of Active Orbital Spaces
• Qulacs: a fast and versatile quantum circuit simulator for research purpose
• Automated construction of molecular active spaces from atomic valence orbitals
• A driven similarity renormalization group approach to quantum many-body problems
• Quantum Krylov subspace algorithms for ground and excited state energy estimation
• Quantum Power Method by a Superposition of Time-Evolved States
• Adiabatic state preparation study of methylene
• Workflow for practical quantum chemical calculations with quantum phase estimation algorithm: electronic ground and π-π* excited states of benzene and its derivatives†
• Coupled cluster method tailored with quantum computing