Quantum-classical simulation of two-site dynamical mean-field theory on noisy quantum hardware

Understand

We report on a quantum-classical simulation of the single-band Hubbard model using two-site dynamical mean-field theory (DMFT).

• Our approach uses IBM's superconducting qubit chip to compute the zero-temperature impurity Green's function in the time domain and a classical computer to fit the measured Green's functions and extract their frequency domain parameters.
• We find that the quantum circuit synthesis (Trotter) and hardware errors lead to incorrect frequency estimates, and subsequently to an inaccurate quasiparticle weight when calculated from the frequency derivative of the self-energy.
• These errors produce incorrect hybridization parameters that prevent the DMFT algorithm from converging to the correct self-consistent solution.