Decoherence of encoded quantum registers

In order to eliminate disturbing effects of decoherence, encoding of quantum information in decoherence-free subspaces has been suggested. We analyze the benefits of this concept for a quantum register that is realized in a spin chain in contact with a common bosonic bath. Within a dissipation-less model we provide explicit analytical results for the average fidelity of plain and encoded quantum registers. For the investigation of dissipative spin-boson couplings we employ a master equation of Bloch-Redfield type.Comment: 13 pages, 9 figure

Investigating knowledge management factors affecting Chinese ICT firms performance: An integrated KM framework

This is an Author's Accepted Manuscript of an article published in the Journal of Information Systems Management, 28(1), 19 - 29, 2011, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/10580530.2011.536107.This article sets out to investigate the critical factors of Knowledge Management (KM) which are considered to have an impact on the performance of Chinese information and communication technology (ICT) firms. This study confirms that the cultural environment of an enterprise is central to its success in the context of China. It shows that a collaborated, trusted, and learning environment within ICT firms will have a positive impact on their KM performance

Parallel Sorting of Large Data Volumes on Distributed Memory Multiprocessors

. The use of multiprocessor architectures requires the parallelization of sorting algorithms. A parallel sorting algorithm based on horizontal parallelization is presented. This algorithm is suited for large data volumes (external sorting) and does not suffer from processing skew in presence of data skew. The core of the parallel sorting algorithm is a new adaptive partitioning method. The effect of data skew is remedied by taking samples representing the distribution of the input data. The parallel algorithm has been implemented on top of a shared disk multiprocessor architecture. The performance evaluation of the algorithm shows that it has linear speedup. Furthermore, the optimal degree of CPU parallelism is derived if I/O limitations are taken into account. 1 Introduction Data sorting plays an important role in computer science and has been studied extensively [23]. The problem of sorting is easily understood. In the sequential case, sorting of tuples (i.e. data items) has at lea..

Determination of the branching fractions for K'-meson absorptions a t rest in carbon nuclei

The branching ratios for the primary interactions of K--mesons at rest with carbon nuclei have been determined by means of a heavy-liquid bubble chamber filled with a mixture of hydrocarbons. The results are compared with those obtained in other absorbing media, and the question of the existence of a halo of neutrons at the surface of heavy nuclei is discussed in the light of these new results. © 1977 Società Italiana di Fisica.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe