Using Quantum Annealers to Calculate Ground State Properties of Molecules

Quantum annealers, which make use of the adiabatic theorem to efficiently find the ground state of a physically realizable Hamiltonian, provide an alternative approach to quantum computing. Such devices are currently commercially available and have been successfully applied to several combinatorial and discrete optimization problems. However, the application of quantum annealers to problems in chemistry remains a relatively sparse area of research due to the difficulty in mapping molecular systems to the Ising model Hamiltonian. In this paper we review two different methods for finding the ground state of molecular Hamiltonians using quantum annealers. In addition, we compare the relative effectiveness of each method by calculating some of the ground state properties of a few simple molecules. We find that while each of these methods is capable of accurately predicting the ground state properties of small molecules, neither demonstrates an improvement over modern classical algorithms.