Efficient Mitigation of Depolarizing Errors in Quantum Simulations

To get the best possible results from current quantum simulators error mitigation is essential. In this work we present a simple but effective error mitigation technique based on the assumption that noise in a deep quantum circuit is well described by depolarizing error channels. By measuring the errors directly on the device, we use an error model ansatz to extrapolate the noisy results back to the error-free. We highlight the efficiency of our mitigation via two examples of recent interest in quantum many-body physics: entanglement measurements and real time dynamics of confinement in quantum spin chains. Our technique enables us to get quantitative results from the IBM quantum computers showing signatures of confinement, i.e. we are able to extract the meson masses of the confined excitations which were previously out of reach. Our protocol is device-independent, efficiently implementable and leads to large improvements in results if the dominant errors are due to depolarization.