Accuracy features for quantum process tomography using superconductor   phase qubits
  We propose a method for precision statistical control of quantum processes based on superconductor phase qubits. Using the universal quantum tomography method, we provide a detailed analysis of accuracy of tomography for a 2-qubit gate SQiSW, which arises due to capacitive coupling between qubits. The developed approach could be successfully applied for quality and efficiency problems of superconductor quantum information technologies. 
Yu. I. Bogdanov, S.A. Nuyanzin
quant-ph