Resolving correlated states of benzyne with an error-mitigated contracted quantum eigensolver

The simulation of strongly correlated many-electron systems is one the most promising applications for near-term quantum devices. Here we use a class eigenvalue solvers (presented in Phys. Rev. Lett. 126, 070504 (2021)) which contraction Schr\"odinger equation solved two-electron reduced density matrix (2-RDM) to resolve energy splittings ortho-, meta-, and para-isomers benzyne ${\textrm C_6} {\textrm H_4}$. In contrast traditional variational eigensolver, contracted eigensolver solves an integration (or contraction) onto space. solution anti-Hermitian part (qACSE) provides scalable approach with parameters that has its foundations 2-RDM theory. Experimentally, variety error mitigation strategies enable calculation, including linear shift targeting iterative nature algorithm as well projection convex set approximately $N$-representable 2-RDMs defined by 2-positive (DQG) $N$-representability conditions. relative energies exhibit single-digit millihartree errors, capturing large electron correlation energy, computed natural orbital occupations reflect significant differences isomers.