title: A reconstruction algorithm for compressive quantum tomography using various measurement sets.
abstract: Compressed sensing (CS) has been verified that it offers a significant performance improvement for large quantum systems comparing with the conventional quantum tomography approaches, because it reduces the number of measurements from O(d2) to O(rd log(d)) in particular for quantum states that are fairly pure. Yet few algorithms have been proposed for quantum state tomography using CS specifically, let alone basis analysis for various measurement sets in quantum CS. To fill this gap, in this paper an efficient and robust state reconstruction algorithm based on compressive sensing is developed. By leveraging the fixed point equation approach to avoid the matrix inverse operation, we propose a fixed-point alternating direction method algorithm for compressive quantum state estimation that can handle both normal errors and large outliers in the optimization process. In addition, properties of five practical measurement bases (including the Pauli basis) are analyzed in terms of their coherences and reconstruction performances, which provides theoretical instructions for the selection of measurement settings in the quantum state estimation. The numerical experiments show that the proposed algorithm has much less calculating time, higher reconstruction accuracy and is more robust to outlier noises than many existing state reconstruction algorithms.
authors.affiliation: Department of Automation, University of Science and Technology of China, Hefei, 230027, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zheng
authors.affiliation: Imperial College London, London, W12 0NN, UK.
authors.forename: Kezhi
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Automation, University of Science and Technology of China, Hefei, 230027, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Cong