Error-Mitigation Enabled Multicomponent Quantum Simulations Beyond the Born-Oppenheimer Approximation

2025/11/14 by Delmar G. A. Cabral, Cabral, Delmar G. A., Brandon Allen +15 · 2 citations
Chemistry · Computer Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Advanced Physical and Chemical Molecular Interactions #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Physics (quant-ph)

paper · pdf · doi:10.48550/arxiv.2511.11941

openalex publication_date 2025/11/14 · openalex created_date 2025/11/19 · openalex updated_date 2026/07/28

Abstract

We introduce a multicomponent unitary coupled cluster framework for quantum simulations of molecular systems that incorporate both electronic and nuclear quantum effects beyond the Born-Oppenheimer approximation. Using the nuclear-electronic orbital formalism, we construct mcUCC ansätze for positronium hydride and molecular hydrogen with a quantum proton, and analyze hardware requirements for different excitation truncations. To further reduce resource costs effectively, we employ the local unitary cluster Jastrow ansatz and implement it experimentally on IBM Q's Heron superconducting hardware. With the Physics-Inspired Extrapolation error mitigation protocol, the computed ground-state energies remain within chemical accuracy, consistent with the stated uncertainty level. These results provide the first demonstration of error-mitigated multicomponent correlated simulations on quantum hardware and outline a path toward scalable algorithms unifying electronic and nuclear degrees of freedom.

Citations

• Approximate quantum circuit compilation for proton-transfer kinetics on quantum processors
• Physics-Inspired Extrapolation for efficient error mitigation and hardware certification
• Nuclear-Electronic Orbital Multireference Configuration Interaction for Ground and Excited Vibronic States and Fundamental Insights into Multicomponent Basis Sets
• Error Mitigation by Restricted Evolution
• Toward Accurate Post-Born-Oppenheimer Molecular Simulations on Quantum Computers: An Adaptive Variational Eigensolver with Nuclear-Electronic Frozen Natural Orbitals
• Nonadiabatic nuclear-electron dynamics: a quantum computing approach
• Reference-State Error Mitigation: A Strategy for High Accuracy Quantum Computation of Chemistry
• Quantum Chemistry as a Benchmark for Near-Term Quantum Computers
• OpenFermion: The Electronic Structure Package for Quantum Computers
• Strategies for quantum computing molecular energies using the unitary coupled cluster ansatz
• Self-Consistent Molecular-Orbital Methods. IX. An Extended Gaussian-Type Basis for Molecular-Orbital Studies of Organic Molecules

Cited by

• Convergence of sample-based quantum diagonalization on a variable-length cuprate chain
• Resource Estimation for VQE on Small Molecules: Impact of Fermion Mappings and Hamiltonian Reductions

Related

• Toward Accurate Post-Born-Oppenheimer Molecular Simulations on Quantum Computers: An Adaptive Variational Eigensolver with Nuclear-Electronic Frozen Natural Orbitals
• Quantum Computing Approach to Atomic and Molecular Three-Body Systems
• Efficient classical simulation of large-scale unitary cluster Jastrow circuits
• Scalable Quantum Simulation of Molecular Energies
• Unitary Coupled Cluster: Seizing the Quantum Moment