--- res: bibo_abstract: - A parallel hybrid quantum-classical algorithm for the solution of the quantum-chemical ground-state energy problem on gate-based quantum computers is presented. This approach is based on the reduced density-matrix functional theory (RDMFT) formulation of the electronic structure problem. For that purpose, the density-matrix functional of the full system is decomposed into an indirectly coupled sum of density-matrix functionals for all its subsystems using the adaptive cluster approximation to RDMFT. The approximations involved in the decomposition and the adaptive cluster approximation itself can be systematically converged to the exact result. The solutions for the density-matrix functionals of the effective subsystems involves a constrained minimization over many-particle states that are approximated by parametrized trial states on the quantum computer similarly to the variational quantum eigensolver. The independence of the density-matrix functionals of the effective subsystems introduces a new level of parallelization and allows for the computational treatment of much larger molecules on a quantum computer with a given qubit count. In addition, for the proposed algorithm techniques are presented to reduce the qubit count, the number of quantum programs, as well as its depth. The evaluation of a density-matrix functional as the essential part of our approach is demonstrated for Hubbard-like systems on IBM quantum computers based on superconducting transmon qubits.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Robert foaf_name: Schade, Robert foaf_surname: Schade foaf_workInfoHomepage: http://www.librecat.org/personId=75963 orcid: 0000-0002-6268-539 - foaf_Person: foaf_givenName: Carsten foaf_name: Bauer, Carsten foaf_surname: Bauer foaf_workInfoHomepage: http://www.librecat.org/personId=90082 - foaf_Person: foaf_givenName: Konstantin foaf_name: Tamoev, Konstantin foaf_surname: Tamoev foaf_workInfoHomepage: http://www.librecat.org/personId=50177 - foaf_Person: foaf_givenName: Lukas foaf_name: Mazur, Lukas foaf_surname: Mazur foaf_workInfoHomepage: http://www.librecat.org/personId=90492 orcid: ' 0000-0001-6304-7082' - foaf_Person: foaf_givenName: Christian foaf_name: Plessl, Christian foaf_surname: Plessl foaf_workInfoHomepage: http://www.librecat.org/personId=16153 orcid: 0000-0001-5728-9982 - foaf_Person: foaf_givenName: Thomas foaf_name: Kühne, Thomas foaf_surname: Kühne foaf_workInfoHomepage: http://www.librecat.org/personId=49079 bibo_doi: 10.1103/PhysRevResearch.4.033160 bibo_volume: 4 dct_date: 2022^xs_gYear dct_language: eng dct_publisher: American Physical Society@ dct_title: Parallel quantum chemistry on noisy intermediate-scale quantum computers@ ...