Sublinear-depth Quantum Simulation of Electrons with Atomic Orbitals
Abstract
Discretizing electronic degrees of freedom into atomic orbitals is the default choice to accurately model electrons in molecules in a compact and flexible way. We consider the task of simulating such electronic structure models on a quantum computer for N orbitals, keeping the number of orbitals per atom constant. Atomic orbitals give rise to Hamiltonians with potentially up to 𝒪(N4) terms and little structure, which made it challenging to match the complexity of methods based on plane waves and real-space grids. In this work, we show that a Trotter step for atomic orbitals can be implemented in depth 𝒪(polylog(N)) without ancillas by combining a rigorous treatment of orbital localization, a hierarchical Hamiltonian decomposition based on the Fast Multipole Method, and shallow quantum Fourier arithmetic circuits. By bounding the Trotter error, we obtain sublinear simulation depth, and our total gate count N5/3 + o(1) matches the best scaling known for any basis.
Related
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- Efficient quantum simulation of unitary gates based on atomic ensembles
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- Production of lepton-flavor-violating scalars through resonant positive-muon annihilation on atomic electrons
BibTeX
@misc{gunther2026sublineardepth,
title = {{Sublinear-depth Quantum Simulation of Electrons with Atomic Orbitals}},
author = {Jakob Günther and Aram W. Harrow},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.00950},
eprint = {2610.00950},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.00950},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Sublinear-depth Quantum Simulation of Electrons with Atomic Orbitals
AU - Jakob Günther
AU - Aram W. Harrow
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.00950
UR - https://arxiv.org/abs/2610.00950
AB - Discretizing electronic degrees of freedom into atomic orbitals is the default choice to accurately model electrons in molecules in a compact and flexible way. We consider the task of simulating such electronic structure models on a quantum computer for N orbitals, keeping the number of orbitals per atom constant. Atomic orbitals give rise to Hamiltonians with potentially up to 𝒪(N^4) terms and little structure, which made it challenging to match the complexity of methods based on plane waves and real-space grids. In this work, we show that a Trotter step for atomic orbitals can be implemented in depth 𝒪(polylog(N)) without ancillas by combining a rigorous treatment of orbital localization, a hierarchical Hamiltonian decomposition based on the Fast Multipole Method, and shallow quantum Fourier arithmetic circuits. By bounding the Trotter error, we obtain sublinear simulation depth, and our total gate count N^5/3 + o(1) matches the best scaling known for any basis.
ER -