Realistic simulations of neutron-neutron scattering on an efficient quantum processing unit

Real time simulations of quantum systems holds the key to modeling and understanding the dynamics and responses of strongly interacting many-body systems such as atomic nuclei and their interactions with other matter. Classical calculations of such systems are plagued by an exponential growth of particle configurations while the simulated dynamics is plagued by sign problems and inverse problems. Quantum processing units (QPU) provide a pathway to simulate the real time evolution of these systems with a polynomial scaling, no sign problem, and no inverse problem; However, current QPUs are too noisy to implement and execute the formal quantum computing algorithms that have been proposed to compute such real time dynamics. This limitation manifests as a limit in the number of gates that can be applied before the QPU enters a decoherent state and information about the simulated dynamics is lost. We demonstrate an alternative efficient high-fidelity encoding of the many-body dynamics onto the QPU and apply it to the realtime simulation of neutron scattering using Hamiltonian derived from chiral effective field theory including realistic pion exchanges. We will present both simulated data and real data taken on the Lawrence Livermore National Lab’s quantum testbed.