ExcitationSolve - A fast gradient-free optimization of excitations in fixed and adaptive VQEs

Abstract

In recent years, the variational quantum eigensolver (VQE) has carried the hope of the quantum computing community for achieving quantum utility. It aims to find the ground state and corresponding energy of a molecular hamiltonian by classically optimizing the parameters of a variational quantum circuit. In order to guarantee the conservation of qunatities such as particle number or spin, physically inspired ansätze such as the UCCSD ansatz are most promising. ExcitationSolve provides a quantum-aware optimizer for such physically inspired ansätze, making best use of prior knowlege about the operators used in the ansatz.