Spectral features of polaronic excitations in a superconducting analog simulator

We investigate spectral properties of polaronic excitations within the framework an analog quantum simulator based on inductively coupled superconducting transmon qubits and microwave resonators. This system emulates a lattice model that describes nonlocal coupling itinerant spinless-fermion excitation to dispersionless (Einstein-type) phonons through Peierls breathing-mode interaction mechanisms. The is characterized by sharp, level-crossing transition at critical value effective excitation-phonon strength; above point, ground state this corresponds heavily dressed (small-polaron) excitation. Using kernel-polynomial method, we evaluate momentum-frequency resolved function for broad range parameters. In particular, underscore ramifications fact zero-quasimomentum Bloch bare represents exact eigenstate Hamiltonian arbitrary strength. also show -- numerically evaluated its well-known relation with survival probability initial, bare-excitation (the Loschmidt echo) one can make predictions about dynamics following quench. To contact anticipated experimental realizations, utilize previously proposed method extracting dynamical-response functions in systems local (single-qubit) addressability using multiqubit (many-body) version Ramsey interference protocol.