Leveraging Randomized Compiling for the QITE Algorithm*

Recent progress on quantum hardware has enabled the successful implementation of quantum algorithms to simulate small molecules or textbook condensed matter models on a limited number of qubits. The results of quantum algorithms executed on such NISQ hardware are, however, limited by the remaining noise, mainly on the multi-qubit gates. Randomized compiling has recently been shown to mitigate the coherent part of the noise to, easier to handle, stochastic noise. In this work, we implement a new noise-mitigation technique, taking advantage of the noise tailoring property of randomized compiling, and then compensating for the stochastic noise. We apply this method to the quantum imaginary time evolution (QITE) algorithm which has attracted a lot of attention recently and is very sensitive to the measurement of expectation values, making it a good benchmark for our scheme. Our method is simple to implement and does not require any additional hardware.