TY - JOUR A1 - Henkel, Carsten A1 - Chin, Y. A1 - Langer, Norbert A1 - Mauersberger, R. T1 - Detection of extragalactic 15N : Nitrogen nucleosynthesis and chemical evolution Y1 - 1999 ER - TY - JOUR A1 - Chin, Y. A1 - Henkel, Carsten A1 - Langer, Norbert A1 - Mauersberger, R. T1 - The detection of extragalactic 15N : consequences for nitrogeen nucleosynthesis and chemical evolution Y1 - 1999 ER - TY - JOUR A1 - Marzoli, Irene A1 - Tombesi, Paolo A1 - Ciaramicoli, Giacomo A1 - Werth, Guenther A1 - Bushev, Pavel A1 - Stahl, S. A1 - Schmidt-Kaler, Ferdinand A1 - Hellwig, Michael A1 - Henkel, Carsten A1 - Marx, Gerrit A1 - Jex, Igor A1 - Stachowska, Ewa A1 - Szawiola, Gustaw A1 - Walaszyk, Adrian T1 - Experimental and theoretical challenges for the trapped electron quantum computer N2 - We discuss quantum information processing with trapped electrons. After recalling the operation principle of planar Penning traps, we sketch the experimental conditions to load, cool and detect single electrons. Here we present a detailed investigation of a scalable scheme including feasibility studies and the analysis of all important elements, relevant for the experimental stage. On the theoretical side, we discuss different methods to couple electron qubits. We estimate the relevant qubit coherence times and draw implications for the experimental setting. A critical assessment of quantum information processing with trapped electrons concludes the paper. Y1 - 2009 UR - http://iopscience.iop.org/0953-4075/ U6 - https://doi.org/10.1088/0953-4075/42/15/154010 SN - 0953-4075 ER - TY - JOUR A1 - Carminati, Rémi A1 - Greffet, Jean-Jacques A1 - Henkel, Carsten A1 - Vigoureux, Jean-Marie T1 - Radiative and non-radiative decay of a single molecule close to a metallic nanoparticle N2 - We study the spontaneous emission of a single emitter close to a metallic nanoparticle, with the aim to clarify the distance dependence of the radiative and non-radiative decay rates. We derive analytical formulas based on a dipole- dipole model, and show that the nonradiative decay rate follows a R-6 dependence at short distance, where R is the distance between the emitter and the center of the nanoparticle, as in Forster's energy transfer. The distance dependence of the radiative decay rate is more subtle. It is chiefly dominated by a R-3 dependence, a R-6 dependence being visible at plasmon resonance. The latter is a consequence of radiative damping in the effective dipole polarizability of the nanoparticle. The different distance behavior of the radiative and non-radiative decay rates implies that the apparent quantum yield always vanishes at short distance. Moreover, non-radiative decay is strongly enhanced when the emitter radiates at the plasmon-resonance frequency of the nanoparticle. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/00304018 U6 - https://doi.org/10.1016/j.optcom.2005.12.009 SN - 0030-4018 ER - TY - JOUR A1 - Westbrook, N. A1 - Henkel, Carsten A1 - Westbrook, C. I. A1 - Landragin, A. A1 - Labeyrie, G. A1 - Cognet, L. A1 - Savalli, V. A1 - Horvath, G. A1 - Aspect, Alain A1 - Moelmer, Klaus A1 - Courtois, J.-Y. A1 - Phillips, W. D. A1 - Kaiser, Rolf A1 - Bagnato, V. T1 - New physics with evanescent wave atomic mirrors : the van der Waals force and atomic diffraction N2 - After a brief introduction to the field of atom optics and to atomic mirrors, we present experimental results obtained in our group during the last two years while studying the reflection of rubidium atoms by an evanescent wave. These involve the first measurement of the van der Waals force between an atom in its ground state and a dielectric wall, as well as the demonstration of a reflection grating for atoms at normal incidence. We also consider the influence of quantum reflection and tunnelling phenomena. Further studies using the atomic mirror as a probe of the van der Waals interaction, and of very small surface roughness are briefly discussed. Y1 - 1998 ER - TY - JOUR A1 - Zhang, Bo A1 - Henkel, Carsten T1 - Magnetic noise around metallic microstructures N2 - We compute the local spectrum of the magnetic field near a metallic microstructure at finite temperature. Our main focus is on deviations from a plane-layered geometry for which we review the main properties. Arbitrary geometries are handled with the help of numerical calculations based on surface integral equations. The magnetic noise shows a significant polarization anisotropy above flat wires with finite lateral width, in stark contrast to an infinitely wide wire. Within the limits of a two-dimensional setting, our results provide accurate estimates for loss and dephasing rates in so-called `atom chip traps' based on metallic wires. A simple approximation based on the incoherent summation of local current elements gives qualitative agreement with the numerics, but fails to describe current correlations among neighboring objects. Y1 - 2007 UR - http://dx.doi.org/10.1063/1.2800174 U6 - https://doi.org/10.1063/1.2800174 SN - 0021-8979 ER - TY - JOUR A1 - Greffet, Jean-Jacques A1 - Henkel, Carsten T1 - Rayonnement thermique cohérent N2 - Le rayonnement électromagnétique produit par un corps à température T est généralement considéré comme l'exemple type du rayonnement incohérent que l'on oppose au rayonnement laser. L'un est quasi isotrope tandis que l'autre est très directionnel, l'un a un large spectre tandis que l'autre est quasi-monochromatique. Aussi surprenant que cela puisse paraître, le rayonnement thermique de bon nombre de corps est cohérent lorsque l'on se place à une distance inférieure à la longueur d'onde de la surface émettrice. Nous verrons que ces effets peuvent être prédits à l'aide d'une approche électromagnétique du rayonnement thermique. Plusieurs expériences récentes ont confirmé ces propriétés inattendues. Y1 - 2006 UR - http://www.cnrs.fr/publications/imagesdelaphysique/Auteurs2006/11_Rayonnement_thermique.html SN - 0290-0041 ER - TY - JOUR A1 - Intravaia, Francesco A1 - Henkel, Carsten A1 - Lambrecht, Astrid T1 - Role of surface plasmons in the Casimir effect N2 - In this paper we study the role of surface plasmon modes in the Casimir effect. The Casimir energy can be written as a sum over the modes of a real cavity and one may identify two sorts of modes, two evanescent surface plasmon modes and propagative modes. As one of the surface plasmon modes becomes propagative for some choice of parameters we adopt an adiabatic mode definition where we follow this mode into the propagative sector and count it together with the surface plasmon contribution, calling this contribution ``plasmonic''. We evaluate analytically the contribution of the plasmonic modes to the Casimir energy. Surprisingly we find that this becomes repulsive for intermediate and large mirror separations. The contribution of surface plasmons to the Casimir energy plays a fundamental role not only at short but also at large distances. This suggests possibilities to taylor the Casimir force via a manipulation of the surface plasmon properties. Y1 - 2007 UR - http://dx.doi.org/10.1103/PhysRevA.76.033820 ER - TY - JOUR A1 - Greffet, Jean-Jacques A1 - Henkel, Carsten T1 - Coherent thermal radiation N2 - The radiation emitted by a heated body is generally quoted as a typical example of incoherent radiation, in distinction to laser radiation. One is nearly isotropic, the other highly directional; one is spectrally broad, the other quasi-monochromatic. It may come as a surprise that the thermal radiation of a large number of substances is coherent, both in space and time, when it is observed at a distance from the body that is shorter than the wavelength. This behaviour can be understood within an electromagnetic approach to thermal emission. Several recent experiments have confirmed these unexpected properties. Y1 - 2007 UR - http://dx.doi.org/10.1080/00107510701690380 SN - 0010-7514 ER - TY - JOUR A1 - Henkel, Carsten T1 - Laser theory in manifest Lindblad form N2 - We discuss the laser theory for a single-mode laser with nonlinear gain. We focus in particular on a micromaser which is pumped with a dilute beam of excited atoms crossing the laser cavity. In the weak-coupling regime, an expansion in the coupling strength is developed that preserves the Lindblad form of the master equation, securing the positivity of the density matrix. This can be improved with an alternative approach, not restricted to weak coupling: the Lindblad operators are expanded in orthogonal polynomials adapted to the probability distribution for the atom-laser interaction time. Results for the photon statistics and the laser linewidth illustrate the theory. Y1 - 2007 UR - http://dx.doi.org/10.1088/0953-4075/40/12/012 SN - 0953-4075 ER -