Mediator assisted cooling in quantum annealing

We show a significant reduction of errors for an architecture of quantum annealing where bosonic modes mediate the interaction between qubits. These systems have a large redundancy in the subspace of solutions, as there are solutions with arbitrarily bosonic occupancies. We explain how this redundancy leads to a mitigation of errors when the bosonic modes work in the ultra-strong coupling regime. Our numerical simulations predict a large increase of qubits coherence for an specific annealing problem with mediated interactions. We provide evidences that error reduction could also occurs in other types of quantum computers with similar architectures.