Here, in this work, we combine the recently developed double unitary coupled cluster (DUCC) theory with the adaptive, problem-tailored variational quantum eigensolver (ADAPT-VQE) to explore the accuracy of unitary downfolded Hamiltonians for quantum simulation of chemistry. We benchmark the ability of DUCC effective Hamiltonians to recover dynamical correlation energy outside of an active space. We consider the effects of strong correlation, commutator truncation, higher-body terms, and approximate external amplitudes on the accuracy of these effective Hamiltonians. When combining these DUCC Hamiltonians with ADAPT-VQE, we observe similar convergence of the ground state as compared with bare active space Hamiltonians, demonstrating that DUCC Hamiltonians provide increased accuracy without increasing the load on the quantum processor.
Singh, Harjeet, et al. "Qubit-Efficient Quantum Chemistry with the ADAPT Variational Quantum Eigensolver and Double Unitary Downfolding." Journal of Chemical Theory and Computation, vol. 21, no. 18, Sep. 2025. https://doi.org/10.1021/acs.jctc.5c00896
Singh, Harjeet, Bertels, Luke W., Claudino, Daniel Chaves, Economou, Sophia E., Barnes, Edwin, Bauman, Nicholas P., Kowalski, Karol, & Mayhall, Nicholas J. (2025). Qubit-Efficient Quantum Chemistry with the ADAPT Variational Quantum Eigensolver and Double Unitary Downfolding. Journal of Chemical Theory and Computation, 21(18). https://doi.org/10.1021/acs.jctc.5c00896
Singh, Harjeet, Bertels, Luke W., Claudino, Daniel Chaves, et al., "Qubit-Efficient Quantum Chemistry with the ADAPT Variational Quantum Eigensolver and Double Unitary Downfolding," Journal of Chemical Theory and Computation 21, no. 18 (2025), https://doi.org/10.1021/acs.jctc.5c00896
@article{osti_3002467,
author = {Singh, Harjeet and Bertels, Luke W. and Claudino, Daniel Chaves and Economou, Sophia E. and Barnes, Edwin and Bauman, Nicholas P. and Kowalski, Karol and Mayhall, Nicholas J.},
title = {Qubit-Efficient Quantum Chemistry with the ADAPT Variational Quantum Eigensolver and Double Unitary Downfolding},
annote = {Here, in this work, we combine the recently developed double unitary coupled cluster (DUCC) theory with the adaptive, problem-tailored variational quantum eigensolver (ADAPT-VQE) to explore the accuracy of unitary downfolded Hamiltonians for quantum simulation of chemistry. We benchmark the ability of DUCC effective Hamiltonians to recover dynamical correlation energy outside of an active space. We consider the effects of strong correlation, commutator truncation, higher-body terms, and approximate external amplitudes on the accuracy of these effective Hamiltonians. When combining these DUCC Hamiltonians with ADAPT-VQE, we observe similar convergence of the ground state as compared with bare active space Hamiltonians, demonstrating that DUCC Hamiltonians provide increased accuracy without increasing the load on the quantum processor.},
doi = {10.1021/acs.jctc.5c00896},
url = {https://www.osti.gov/biblio/3002467},
journal = {Journal of Chemical Theory and Computation},
issn = {ISSN 1549-9618},
number = {18},
volume = {21},
place = {United States},
publisher = {American Chemical Society},
year = {2025},
month = {09}}
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); USDOE Laboratory Directed Research and Development (LDRD) Program
Grant/Contract Number:
SC0025430; SC0024619; AC05-00OR22725
OSTI ID:
3002467
Journal Information:
Journal of Chemical Theory and Computation, Journal Name: Journal of Chemical Theory and Computation Journal Issue: 18 Vol. 21; ISSN 1549-9626; ISSN 1549-9618