Leadership and power

Leadership does not exist without power. Thus we have to reflect on power in order to lay a theoretical foundation for responsible leadership. This interdisciplinary article collects insights from the disciplines of theology, sociology, and crosscultural management. It provides a concise summary of what a Christian leader should know about power in order to use his/her power in an adequate way. The theological reflection reminds us of the fact that, according to the Judeo-Christian tradition, God gave power to humankind (Guardini, 1998). Two opposite dangers are described in this article, namely the abuse of power on the one hand and the misconception of powerlessness as a Christian virtue on the other hand. The sociological section describes different forms of power. Following French and Raven (1960), it introduces seven power bases, which are illustrated by examples from society and the church. The next section describes the different cultural perceptions on power. It shows how the cultural parameter of power distance may influence the appropriate leadership style (Hofstede & Hofstede, 2005). It is argued that our understanding of a right or wrong use of power is strongly influenced by the culture in which we grew up. The article concludes with a list of ethical guidelines on the use of power for responsible Christian leaders

Tunable Superconducting Phase Transition in Metal-Decorated Graphene Sheets

Using typical experimental techniques it is difficult to separate the effects of carrier density and disorder on the superconducting transition in two dimensions. Using a simple fabrication procedure based on metal layer dewetting, we have produced graphene sheets decorated with a non-percolating network of nanoscale tin clusters. These metal clusters both efficiently dope the graphene substrate and induce long-range superconducting correlations. This allows us to study the superconducting transition at fixed disorder and variable carrier concentration. We find that despite structural inhomogeneity on mesoscopic length scales (10-100 nm), this material behaves electronically as a homogenous dirty superconductor. Our simple self-assembly method establishes graphene as an ideal tunable substrate for studying induced two-dimensional electronic systems at fixed disorder and our technique can readily be extended to other order parameters such as magnetism

Editorial

The purpose of this special issue is to highlight the importance of Christian leadership and to stress that the context within which leadership is reflected upon and exercised is important. All of the articles discuss aspects of leadership from a Christian theological perspective. We believe that an ongoing debate on leadership is important given the vast potential for good leadership to have a positive impact on the world. The contribution of Christians to this debate is vital, since people in all countries of the world suffer because of malign and destructive forms of leadership

A Preliminary Look at the Physics Reach of a Solar Neutrino TPC: Time-Independent Two Neutrino Oscillations

This paper will discuss the physics reach of a solar neutrino TPC containing many tons of He4 under high pressure. Particular attention is given to the LMA and SMA solutions, which are allowed by current data, and which are characterized by a lack of time-dependent phenomena (either summer-winter or day-night asymmetries). In this case, the physics of neutrino masses and mixing is all contained in the energy dependence of the electron neutrino survival probability, (or in its reciprocal, the electron neutrino disappearance probability).Comment: 19 pages, 12 figure

Extinction Rates for Fluctuation-Induced Metastabilities : A Real-Space WKB Approach

The extinction of a single species due to demographic stochasticity is analyzed. The discrete nature of the individual agents and the Poissonian noise related to the birth-death processes result in local extinction of a metastable population, as the system hits the absorbing state. The Fokker-Planck formulation of that problem fails to capture the statistics of large deviations from the metastable state, while approximations appropriate close to the absorbing state become, in general, invalid as the population becomes large. To connect these two regimes, a master equation based on a real space WKB method is presented, and is shown to yield an excellent approximation for the decay rate and the extreme events statistics all the way down to the absorbing state. The details of the underlying microscopic process, smeared out in a mean field treatment, are shown to be crucial for an exact determination of the extinction exponent. This general scheme is shown to reproduce the known results in the field, to yield new corollaries and to fit quite precisely the numerical solutions. Moreover it allows for systematic improvement via a series expansion where the small parameter is the inverse of the number of individuals in the metastable state

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Quantum network of neutral atom clocks

We propose a protocol for creating a fully entangled GHZ-type state of neutral atoms in spatially separated optical atomic clocks. In our scheme, local operations make use of the strong dipole-dipole interaction between Rydberg excitations, which give rise to fast and reliable quantum operations involving all atoms in the ensemble. The necessary entanglement between distant ensembles is mediated by single-photon quantum channels and collectively enhanced light-matter couplings. These techniques can be used to create the recently proposed quantum clock network based on neutral atom optical clocks. We specifically analyze a possible realization of this scheme using neutral Yb ensembles.Comment: 13 pages, 11 figure

Optical Superradiance from Nuclear Spin Environment of Single Photon Emitters

We show that superradiant optical emission can be observed from the polarized nuclear spin ensemble surrounding a single photon emitter such as a single quantum dot (QD) or Nitrogen-Vacancy (NV) center. The superradiant light is emitted under optical pumping conditions and would be observable with realistic experimental parameters.Comment: 4+ pages, 3 figures, considerably rewritten, conclusions unchanged, accepted versio

Microscopic Selection of Fluid Fingering Pattern

We study the issue of the selection of viscous fingering patterns in the limit of small surface tension. Through detailed simulations of anisotropic fingering, we demonstrate conclusively that no selection independent of the small-scale cutoff (macroscopic selection) occurs in this system. Rather, the small-scale cutoff completely controls the pattern, even on short time scales, in accord with the theory of microscopic solvability. We demonstrate that ordered patterns are dynamically selected only for not too small surface tensions. For extremely small surface tensions, the system exhibits chaotic behavior and no regular pattern is realized.Comment: 6 pages, 5 figure

Finding oneself? Contemplating on paintings with a religious theme in clinical pastoral care

This article is based on intra- and interdisciplinary explorative research on contemplating art with a religious theme in the context of clinical pastoral care. The study, done in a rehabilitation hospital in Bavaria, Germany, explores the emotions, feelings, and thoughts aroused by contemplating on Rembrandt’s painting, The return of the prodigal son. It includes guided observations of the painting, voluntary feedback on forms, and eight interviews on what could be observed under the aspects of self-reflection, identification, and reorientation. Aspects of aesthetics, biography, religion, and emotion are also observed. The evaluation of the aesthetic reception shows two types of reactions, namely identification with a person or a theme of the painting. It is observed that self-reflection, an important factor for reorientation during the process of clinical pastoral care, is present in all interviewees. Each interviewee presents an individual characteristic related to their life situation. Core themes corresponding to the painting’s content are guilt, forgiveness, mercy, and reorientation. The practice of contemplation on paintings with a religious theme, using methods common in the social sciences and empirical theology, represents one possibility among many in the field of clinical pastoral care. The study provides new information on the therapeutic possibilities of creative experiences, by contemplating on paintings that can be explored further.&nbsp