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

We report on a quantum-classical simulation of a two-site dynamical mean-field theory (DMFT) calculation. We use 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 function. We find that Trotter errors and noise from the quantum chip lead to inaccurate updates to impurity parameters, preventing the DMFT algorithm from converging to the correct solution. To mitigate this issue, we determine the update to the hybridization parameter by integrating the low-frequency peaks in the spectral function. This allows us to iterate the DMFT loop to self-consistency for a strongly Mott insulating system at half-filling.