Year: 2026
Type: article
Abstract: Quantum algorithms offer a promising route toward computational advantage, but current implementations remain constrained by limited coherence and gate errors, making circuit complexity and noise sensitivity critical considerations. Here, we develop a shortcuts-to-adiabaticity strategy for molecular ground-state preparation and apply it to both digitized adiabatic quantum computing and the variational quantum eigensolver. In the adiabatic framework, we construct an approximate counterdiabatic (CD) Hamiltonian using a nested-commutator expansion. For the molecular systems considered, the CD correction accelerates state preparation and improves energy convergence in the fast-evolution regime, enabling a target accuracy to be reached with a lower implemented-operator count. In the variational setting, we introduce the adiabatic gauge ansatz ($\mbox{AGA}$), obtained by promoting the Pauli-string components generated by the approximate adiabatic gauge potential (AGP) to independent variational generators. We further propose a reduced variant, $\mbox{AGAR}$, that retains only Pauli generators with weight not larger than two, substantially reducing the ansatz size while maintaining competitive accuracy over the regimes considered. Benchmarks on $\mathrm{LiH}$ and $\mathrm{BeH}_2$ show that the proposed ansätze achieve accuracies competitive with established approaches such as UCCSD. Experiments on the \texttt{IBM\_basquecountry} superconducting quantum processor, together with simulations under depolarizing noise, show that the reduced CD-inspired ansatz yields smaller energy discrepancies than UCCSD under the noise conditions considered. Overall, our results demonstrate how AGP-inspired operator structures can be used to balance accuracy and implementation cost in molecular simulations on current noise-limited quantum hardware.
Source: Physical Review A
DOI: 10.1103/rpnt-v9mr
Author: Anonymous
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
Awards: G121809054, G1622782223, G1855990336, G2262748287, G2660406951, G3480869486, G3496905377, G3553972928, G3681454997, G3777708657, G3809973144, G3861891927, G4042783231, G425668148, Electronic-photonic integrated quantum simulator platform, G451917667, G5421974903, Open Superconducting Quantum Computers (OpenSuperQPlus), G5967599077, G5987792135, G6293336981, G6604905309, G67347242, G7084143925, G7291322435, G8738040877, G8953647516
OpenAlex ID: W4401203374