Mapping Hamiltonians from material science onto near-term quantum devices

Simulation of quantum Hamiltonians is one of the most promising applications proposed for which quantum hardware may provide significant advances over classical methods. However, significant limitations on near-term hardware size and fidelity pose a significant challenge for implementing known methods for realistic applications in chemistry and material science. Finding realistic systems for which near-term hardware can produce a useful simulation remains an open question. In this work we demonstrate that downfolding Hamiltonians, a process by which real materials are mapped on to model Hamiltonians, can yield a Hamiltonian form and size that is suitable for simulation on near-term quantum hardware. We apply this approach to several example materials and show how to implement it on realistic hardware using generalized swap networks.