We analyze the quantum process tomography (QPT) in the presence of decoherence, focusing on distinguishing local and non-local decoherence mechanisms for a two-partite system from experimental QPT data. In particular, we consider the iSWAP gate realized with superconducting phase qubits and calculate the QPT matrix χ in the presence of several local and non-local decoherence processes. We determine specific patterns of these decoherence processes, which can be used for a fast identification of the main decoherence mechanisms from an experimental χ-matrix.
@article{arxiv.0903.0671,
title = {Two-qubit decoherence mechanisms revealed via quantum process tomography},
author = {A. G. Kofman and A. N. Korotkov},
journal= {arXiv preprint arXiv:0903.0671},
year = {2015}
}