Quantum-Enhanced Sensing Based on Time Reversal of Nonlinear Dynamics

We experimentally demonstrate a nonlinear detection scheme exploiting time-reversal dynamics that disentangles continuous variable entangled states for feasible readout. Spin-exchange dynamics of Bose-Einstein condensates is used as the nonlinear mechanism which not only generates entangled states but can also be time reversed by controlled phase imprinting. For demonstration of a quantum-enhanced measurement we construct an active atom SU(1,1) interferometer, where entangled state preparation and nonlinear readout both consist of parametric amplification. This scheme is capable of exhausting the quantum resource by detecting solely mean atom numbers. Controlled nonlinear transformations widen the spectrum of useful entangled states for applied quantum technologies.Comment: 9 pages, 3 figures, 3 pages supplementary material, 2 supplementary figure

„Es war kein Job, es war eine Berufung" – Gouvernementale Führung, fragmentierte Subjekte und <i>contre-conduite</i> in der nichtstaatlichen Entwicklungspraxis

With their donation appeals aid organisations procure a polarised worldview of the self and other into our everyday lives and feed on discourses of “development” and “neediness”. This study investigates how the discourse of “development” is embedded in the subjectivities of “development” professionals. By approaching the topic from a governmentality perspective, the paper illustrates how “development” is (re-)produced through internalised Western values and powerful mechanisms of self-conduct. Meanwhile, this form of self-conduct, which is related to a “good cause”, also gives rise to doubts regarding the work, as well as fragmentations and shifts of identity. On the one hand, the paper outlines various coping strategies used by development professionals to maintain a coherent narrative about the self. On the other hand, it also shows how doubts and fragmentations of identity can generate a critical distance to “development” practice, providing a space for resistant and transformative practice in the sense of Foucauldian counter-conduct.</p

A Proposal to Localize Fermi GBM GRBs Through Coordinated Scanning of the GBM Error Circle via Optical Telescopes

We investigate the feasibility of implementing a system that will coordinate ground-based optical telescopes to cover the Fermi GBM Error Circle (EC). The aim of the system is to localize GBM detected GRBs and facilitate multi-wavelength follow-up from space and ground. This system will optimize the observing locations in the GBM EC based on individual telescope location, Field of View (FoV) and sensitivity. The proposed system will coordinate GBM EC scanning by professional as well as amateur astronomers around the world. The results of a Monte Carlo simulation to investigate the feasibility of the project are presented.Comment: 2011 Fermi Symposium proceedings - eConf C11050