Reducing PEC Overhead by Pauli Error Propagation

Abstract: Quantum error mitigation is regarded as a possible path to near-term quantum utility. The methods under the quantum error mitigation umbrella term, such as probabilistic error cancellation, zero-noise extrapolation or Clifford data regression are able to significantly reduce the error for the estimation of expectation values, although at an exponentially scaling cost, i.e., in the sampling overhead. In this work, we present a straightforward method for reducing the sampling overhead of PEC on Clifford circuits (and Clifford subcircuits) via Pauli error propagation alongside some classical preprocessing. While the methods presented in this work are restricted to Clifford circuits, we argue that Clifford sub circuits often occur in relevant calculations as for example the resource state generation in measurement based quantum computing.