Reference-state Error Mitigation: A Chemistry Inspired Strategy for Improving Molecular Energy Evaluations on NISQ Devices

Current and near-term quantum computational hardware suffers from various forms of noise that limit their potential advantage [1]. This presentation outlines a strategy for mitigating the effects of systematic hardware-errors on quantum chemical calculations performed using the Variational Quantum Eigensolver algorithm. The Reference-State Error Mitigation (REM) strategy can be straightforwardly implemented on current devices, requiring at most one additional measurement of the molecular Hamiltonian, followed by minimal post-processing. Some of the most precise energy evaluations on a real quantum device to date is demonstrated by combining REM with VQE calculations of small molecules, including H₂, HeH⁺, LiH, and BeH₂. The strategy can be applied concurrently with other error mitigation techniques, such as readout error mitigation, and offers a marked improvement for treating chemical problems on both current and future devices.

 

 

[1]  Cao,  et al.  Quantum Chemistry in the Age of Quantum Computing. Chemical Reviews, 119(19):10856–10915, 10 2019.