Quantum Error Mitigation for Quantum State Tomography

Quantum state tomography (QST) is the task of statistically constructing the density matrix of an unknown quantum state by measuring its several copies. The presence of noise in the QST setup can considerably degrade the fidelity between the constructed density matrix and the actual state. We consider a noisy QST setup with depolarizing noise and attempt to mitigate the effects of noise by quantum error mitigation (QEM). We compare the performance of different QEM methods with the same resources and find that the measurement error mitigation and zero noise extrapolation provide the best performance in terms of maximizing the fidelity between the state and its density matrix.