5 research outputs found

    A new tool for miscibility control: Linear coupling

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    In this work we experimentally study the rich interplay of a linear coupling and non-linear interactions between the two components of an elongated Bose-Einstein condensate of 87Rb. In the limit of strong linear coupling we generate dressed states and explore the effective interactions between them. We find that the miscibility of dressed states is opposite to that of the atomic states. If the characteristic energies of interactions and linear coupling are equal they give rise to a miscible-immiscible quantum phase transition. We study the linear response of the system to sudden quenches in the vicinity of the critical point by analyzing spin correlations in the system. A power law scaling of the characteristic length scales is observed on both sides of the phase transition and the scaling exponents agree with the mean field prediction. Temporal scaling is found on the miscible side in agreement with a prediction based on Bogoliubov theory. In addition, experimental results for finite-time quenches through the critical point are presented. The good control over amplitude and phase of the linear coupling field offers new possibilities for the study of both equilibrium and dynamical properties of phase transitions

    Classical bifurcation at the transition from Rabi to Josephson dynamics

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    We report on the experimental realization of an internal bosonic Josephson junction in a Rubidium spinor Bose-Einstein condensate. The measurement of the full time dynamics in phase space allows the characterization of the theoretically predicted π\pi-phase modes and quantitatively confirms analytical predictions, revealing a classical bifurcation. Our results suggest that this system is a model system which can be tuned from classical to the quantum regime and thus is an important step towards the experimental investigation of entanglement generation close to critical points

    Receptor for advanced glycation end products (RAGE) regulates sepsis but not the adaptive immune response

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    This is the publisher's version, also available electronically from http://www.jci.org/articles/view/18704While the initiation of the adaptive and innate immune response is well understood, less is known about cellular mechanisms propagating inflammation. The receptor for advanced glycation end products (RAGE), a transmembrane receptor of the immunoglobulin superfamily, leads to perpetuated cell activation. Using novel animal models with defective or tissue-specific RAGE expression, we show that in these animal models RAGE does not play a role in the adaptive immune response. However, deletion of RAGE provides protection from the lethal effects of septic shock caused by cecal ligation and puncture. Such protection is reversed by reconstitution of RAGE in endothelial and hematopoietic cells. These results indicate that the innate immune response is controlled by pattern-recognition receptors not only at the initiating steps but also at the phase of perpetuation