Standardisation, Innovation and Implementation of Information Technology

This paper looks at the mutual interplay between information technology (IT) and its environment. Exploring specifically the issues surrounding innovations in the field of corporate IT systems we show that a distinction has to be made between different categories of information technology (IT) systems regarding their introduction, subsequent diffusion, and particularly their corporate usage. We will show that strategic deployment of e-mail will only happen if and when it is no longer considered an infrastructural technology. However, apparently this has rarely happened thus far. Strong relations and dependencies exist between standardiation, innovation and the subsequent implementation of IT systems. We argue that these activities must not be considered separately, especially as standards-based components are playing an increasingly important role in implementation processes. Consequently, the role of the users in, and their influence on, standards setting are addressed as well. The findings and conclusions presented are largely based on a number of interview

Comparative study of theoretical methods for nonequilibrium quantum transport

We present a detailed comparison of three different methods designed to tackle nonequilibrium quantum transport, namely the functional renormalization group (fRG), the time-dependent density matrix renormalization group (tDMRG), and the iterative summation of real-time path integrals (ISPI). For the nonequilibrium single-impurity Anderson model (including a Zeeman term at the impurity site), we demonstrate that the three methods are in quantitative agreement over a wide range of parameters at the particle-hole symmetric point as well as in the mixed-valence regime. We further compare these techniques with two quantum Monte Carlo approaches and the time-dependent numerical renormalization group method.Comment: 19 pages, 7 figures; published versio

Temperature induced phase averaging in one-dimensional mesoscopic systems

We analyse phase averaging in one-dimensional interacting mesoscopic systems with several barriers and show that for incommensurate positions an independent average over several phases can be induced by finite temperature. For three strong barriers with conductances G_i and mutual distances larger than the thermal length, we obtain G ~ sqrt{G_1 G_2 G_3} for the total conductance G. For an interacting wire, this implies power laws in G(T) with novel exponents, which we propose as an experimental fingerprint to distinguish temperature induced phase averaging from dephasing.Comment: 6 pages, 5 figures; added one figure; slightly extende

Exact results for nonlinear ac-transport through a resonant level model

We obtain exact results for the transport through a resonant level model (noninteracting Anderson impurity model) for rectangular voltage bias as a function of time. We study both the transient behavior after switching on the tunneling at time t = 0 and the ensuing steady state behavior. Explicit expressions are obtained for the ac-current in the linear response regime and beyond for large voltage bias. Among other effects, we observe current ringing and PAT (photon assisted tunneling) oscillations.Comment: 7 page

Mitochondrial cristae revealed with focused light.

Because of the diffraction resolution barrier, optical microscopes have so far failed in visualizing the mitochondrial cristae, that is, the folds of the inner membrane of this 200 to 400 nm diameter sized tubular organelle. Realizing a ∼30 nm isotropic subdiffraction resolution in isoSTED fluorescence nanoscopy, we have visualized these essential structures in the mitochondria of intact cells. We find a pronounced heterogeneity in the cristae arrangements even within individual mitochondrial tubules

Prospects for the Search for a Standard Model Higgs Boson in ATLAS using Vector Boson Fusion

The potential for the discovery of a Standard Model Higgs boson in the mass range m_H < 2 m_Z in the vector boson fusion mode has been studied for the ATLAS experiment at the LHC. The characteristic signatures of additional jets in the forward regions of the detector and of low jet activity in the central region allow for an efficient background rejection. Analyses for the H -> WW and H -> tau tau decay modes have been performed using a realistic simulation of the expected detector performance. The results obtained demonstrate the large discovery potential in the H -> WW decay channel and the sensitivity to Higgs boson decays into tau-pairs in the low-mass region around 120 GeV.Comment: 20 pages, 13 ps figures, uses EPJ style fil