Środowiskowe Seminarium z Informacji i Technologii Kwantowych

Quantum devices in the near future will be inevitably noisy and imperfect. Hence it becomes an especially important task to develop error correction and mitigation schemes that would counter the destructive effects of noise and decoherence. The main aim of my talk is to present an error mitigation scheme for measurement (readout) errors of a particular, classical type. First, I will use the formalism of generalized quantum measurements (POVMs) to present a model of such noise. Second, I will show how to mitigate it using solely classical post-processing, provided one has access to knowledge about the noise. I will describe a procedure known as Quantum Detector Tomography, which allows to obtain such knowledge in practice. Furthermore, I will discuss the influence of finite statistics and possible deviations from the noise model, on the applicability of our procedure. Finally, I will present experimental results from IBM quantum devices, which confirm the effectiveness of our mitigation scheme for exemplary single and two-qubit experiments.