Gapless Spin-Fluid Ground State in a Random Quantum Heisenberg Magnet

We examine the spin-$S$ quantum Heisenberg magnet with Gaussian-random, infinite-range exchange interactions. The quantum-disordered phase is accessed by generalizing to $SU(M)$ symmetry and studying the large $M$ limit. For large $S$ the ground state is a spin-glass, while quantum fluctuations produce a spin-fluid state for small $S$. The spin-fluid phase is found to be generically gapless - the average, zero temperature, local dynamic spin-susceptibility obeys \bar{\chi} (\omega ) \sim \log(1/|\omega|) + i (\pi/2) \mbox{sgn} (\omega) at low frequencies. This form is identical to the phenomenological `marginal' spectrum proposed by Varma {\em et. al.\/} for the doped cuprates.Comment: 13 pages, REVTEX, 2 figures available by request from [email protected]

Random Exchange Quantum Heisenberg Chains

The one-dimensional quantum Heisenberg model with random $\pm J$ bonds is studied for $S=\frac{1}{2}$ and $S=1$. The specific heat and the zero-field susceptibility are calculated by using high-temperature series expansions and quantum transfer matrix method. The susceptibility shows a Curie-like temperature dependence at low temperatures as well as at high temperatures. The numerical results for the specific heat suggest that there are anomalously many low-lying excitations. The qualitative nature of these excitations is discussed based on the exact diagonalization of finite size systems.Comment: 13 pages, RevTex, 12 figures available on request ([email protected]

The Man behind the Curtain: Exploring the Role of IS Strategic Consultant

Most organizations encounter business-IT alignment problems because they fail to properly understand how well an enterprise software package aligns with or fits their needs. Strategic consultants make a profit by reducing such external manifestations of the differences between the organization's needs and the system's capabilities. Therefore it appears relevant to understand how consultants behave. Our theoretical model shows how a consultancy can assess the way to extract and to generalize knowledge from its clients. The share of a consulting firm's global knowledge is compensated with new local knowledge obtained from the client. Hence we underline a way to assess the quality of that contribution and the mutual knowledge exchange

Evaluating 1 Thessalonians: an outline of holistic approaches to 1 Thessalonians in the last 25 years

This article focuses on works that have been produced within the last 25 years which attempt to provide a holistic approach to the understanding and interpretation of 1 Thessalonians, such as: epistolary, rhetorical, theological, linguistic, and various combinations of the above. Proponents of each view and their perspectives will be outlined along with their structural division of the text. This article attempts to provide a general map of particular approaches to 1 Thessalonians, but also provides a brief outline of some of the critiques and weaknesses of the different methodologies. This article concludes with a brief statement regarding the trajectory of current studies

Perceived environmental uncertainty; PEU; REF 2014

NoAn important contribution to the literature on perceived environmental uncertainty (PEU) is Milliken’s distinction between state uncertainty, effect uncertainty, and response uncertainty. However, despite its appealing logic in capturing the types of uncertainty managers may experience as they seek to understand and respond to changes in an organization’s environment, there has been no full and rigorous psychometric development and testing of scales to measure the three constructs. Using a two-phase empirical study, this research seeks to develop and test such scales in terms of dimensionality, reliability, and validity (including nomological validity). The results suggest that managers do make a meaningful distinction between different types of uncertainty, that it is worthwhile measuring all three constructs (as they have differential impacts on outcome variables), and that there are linkages between them. Managerial contributions and implications for future research are also discussed