Polarization-based Light-Atom Quantum Interface with an All-optical Trap

We describe the implementation of a system for studying light-matter interactions using an ensemble of $10^6$ cold rubidium 87 atoms, trapped in a single-beam optical dipole trap. In this configuration the elongated shape of the atomic cloud increases the strength of the collective light-atom coupling. Trapping all-optically allows for long storage times in a low decoherence environment. We are able to perform several thousands of measurements on one atomic ensemble with little destruction. We report results on paramagnetic Faraday rotations from a macroscopically polarized atomic ensemble. Our results confirm that strong light-atom coupling is achievable in this system which makes it attractive for single-pass quantum information protocols.Comment: 8 pages, 4 figure

Risks at Work: The Demand and Supply Sides of Government Redistribution

To understand how the welfare state adjusts to economic shocks it is important to explain both the genesis of popular preferences and the institutional incentives of governments to respond to these preferences. This paper attempts to do both, using a general theoretical framework and detailed data at both the individual and national levels. In a first step, we focus on how risk exposure and income are related to preferences for redistribution. To test our hypotheses, we extract detailed risk exposure measures from labor force surveys and marry them to cross-national survey data. In a second step, we turn our attention to the supply side of government redistribution. Institutions, we argue, mediate governments’ reactions to redistributional demands following economic shocks. Using time-series cross-country data, we demonstrate how national training systems, electoral institutions as well as government partisanship shape government responses.Um zu verstehen, wie Wohlfahrtsstaaten auf ökonomische Schocks reagieren, ist es wichtig, sowohl die Nachfrage- als auch die Angebotsseite von Umverteilung zu analysieren. Wie entstehen Umverteilungs-Präferenzen in der Bevölkerung? Welche institutionellen Anreize haben Regierungen, darauf zu reagieren? Das vorliegende Papier wendet einen generellen theoretischen Rahmen und umfangreiche Individual- und Aggregat-Daten an, um diesen Fragen nachzugehen. Dazu wird zuerst analysiert, wie Risiken im Arbeitsmarkt und das Einkommen Umverteilungs-Präferenzen von Individuen beeinflussen. Die abgeleiteten Hypothesen werden an neuen Datensätzen getestet. Diese kombinieren Informationen von Arbeitsmarkterhebungen und Umfrage-Daten für mehrere Länder und Jahre. In Sachen Angebotsseite wird argumentiert, dass unterschiedliche Regierungen auf ökonomische Schocks unterschiedlich reagieren, abhängig von Institutionen. Das Papier testet diese und andere Hypothesen auf der Aggregatsebene anhand von vergleichenden Zeitreihen. Es zeigt sich, dass die Art und Weise, wie Regierungen auf ökonomische Schocks reagieren, von Ausbildungs- und Wahlsystemen sowie der parteipolitischen Färbung der Regierung mitbestimmt werden

Untersuchung zur Betriebsnachfolge im Bereich der Handwerkskammer Stuttgart

SIGLEBibliothek Weltwirtschaft Kiel C 138122 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

In-vivo biomagnetic characterisation of the American cockroach

Abstract We present a quantitative method, utilising a highly sensitive quantum sensor, that extends applicability of magnetorelaxometry to biological samples at physiological temperature. The observed magnetic fields allow for non-invasive determination of physical properties of magnetic materials and their surrounding environment inside the specimen. The method is applied to American cockroaches and reveals magnetic deposits with strikingly different behaviour in alive and dead insects. We discuss consequences of this finding to cockroach magneto-reception. To our knowledge, this work represents the first characterisation of the magnetisation dynamics in live insects and helps to connect results from behavioural experiments on insects in magnetic fields with characterisation of magnetic materials in their corpses

Does Immigration Undermine Public Support for Social Policy?

There has been great interest in the relationship between immigration and the welfare state in recent years, and particularly since Alesina and Glaeser’s (2004) influential work. Following literatures on solidarity and fractionalization, race in the U.S. welfare state, and anti-immigrant sentiments, many contend that immigration undermines public support for social policy. This study analyzes three measures of immigration and six welfare attitudes using 1996 and 2006 International Social Survey Program (ISSP) data for 17 affluent democracies. Based on multi-level and two-way fixed-effects models, our results mostly fail to support the generic hypothesis that immigration undermines public support for social policy. The percent foreign born, net migration, and the 10-year change in the percent foreign born all fail to have robust significant negative effects on welfare attitudes. There is evidence that the percent foreign born significantly undermines the welfare attitude that government “should provide a job for everyone who wants one.” However, there is more robust evidence that net migration and change in percent foreign born have positive effects on welfare attitudes. We conclude that the compensation and chauvinism hypotheses provide greater potential for future research, and we critically consider other ways immigration could undermine the welfare state. Ultimately, this study demonstrates that factors other than immigration are far more important for public support of social policy.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich / This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation).En los últimos años ha surgido un gran interés en la relación entre la inmigración y el estado de bienestar, especialmente a partir del influyente trabajo de Alesina y Glaeser (2004). Con base en la literatura sobre solidaridad y fraccionalización, raza en el estado de bienestar estadounidense y sentimientos en contra de los inmigrantes, muchos sostienen que la inmigración debilita el apoyo público a las políticas sociales. En este estudio se analizan tres medidas sobre inmigración y seis actitudes relativas al bienestar. Para ello utilizamos datos de 17 democracias prósperas del Programa Internacional de Encuestas Sociales (ISSP, según sus siglas en inglés) de 1996 y 2006. Sobre la base de modelos multinivel y de efectos fijos de doble vía, en su mayoría nuestros resultados no logran dar sustento a la hipótesis genérica que sostiene que la inmigración debilita el apoyo público a las políticas sociales. Ni el porcentaje de nacidos en el extranjero, ni la migración neta ni el cambio en diez años del porcentaje de nacidos en el extranjero demostraron tener efectos negativos significativos en las actitudes relativas al bienestar. Existe evidencia de que el porcentaje de nacidos en el extranjero debilita significativamente la actitud relativa al bienestar que indica que el gobierno "debería proporcionar un empleo a todo aquel que lo desee". Sin embargo, existe evidencia más robusta que sugiere que la migración neta y el cambio en el porcentaje de nacidos en el extranjero tienen efectos positivos en las actitudes relativas al bienestar. Concluimos que las hipótesis de la compensación y del chauvinismo proporcionan un potencial mayor para futuras investigaciones y discutimos críticamente otros modos en que la inmigración puede debilitar el estado de bienestar. Por último, en este estudio se demuestra que otros factores distintos de la inmigración son mucho más importantes para el apoyo público a las políticas sociales