@article{HenkelChinLangeretal.1999, author = {Henkel, Carsten and Chin, Y. and Langer, Norbert and Mauersberger, R.}, title = {Detection of extragalactic 15N : Nitrogen nucleosynthesis and chemical evolution}, year = {1999}, language = {en} } @article{ChinHenkelLangeretal.1999, author = {Chin, Y. and Henkel, Carsten and Langer, Norbert and Mauersberger, R.}, title = {The detection of extragalactic 15N : consequences for nitrogeen nucleosynthesis and chemical evolution}, year = {1999}, language = {en} } @article{MarzoliTombesiCiaramicolietal.2009, author = {Marzoli, Irene and Tombesi, Paolo and Ciaramicoli, Giacomo and Werth, Guenther and Bushev, Pavel and Stahl, S. and Schmidt-Kaler, Ferdinand and Hellwig, Michael and Henkel, Carsten and Marx, Gerrit and Jex, Igor and Stachowska, Ewa and Szawiola, Gustaw and Walaszyk, Adrian}, title = {Experimental and theoretical challenges for the trapped electron quantum computer}, issn = {0953-4075}, doi = {10.1088/0953-4075/42/15/154010}, year = {2009}, abstract = {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.}, language = {en} } @article{CarminatiGreffetHenkeletal.2006, author = {Carminati, R{\´e}mi and Greffet, Jean-Jacques and Henkel, Carsten and Vigoureux, Jean-Marie}, title = {Radiative and non-radiative decay of a single molecule close to a metallic nanoparticle}, issn = {0030-4018}, doi = {10.1016/j.optcom.2005.12.009}, year = {2006}, abstract = {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.}, language = {en} } @article{WestbrookHenkelWestbrooketal.1998, author = {Westbrook, N. and Henkel, Carsten and Westbrook, C. I. and Landragin, A. and Labeyrie, G. and Cognet, L. and Savalli, V. and Horvath, G. and Aspect, Alain and Moelmer, Klaus and Courtois, J.-Y. and Phillips, W. D. and Kaiser, Rolf and Bagnato, V.}, title = {New physics with evanescent wave atomic mirrors : the van der Waals force and atomic diffraction}, year = {1998}, abstract = {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.}, language = {en} } @article{ZhangHenkel2007, author = {Zhang, Bo and Henkel, Carsten}, title = {Magnetic noise around metallic microstructures}, issn = {0021-8979}, doi = {10.1063/1.2800174}, year = {2007}, abstract = {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.}, language = {en} } @article{GreffetHenkel2006, author = {Greffet, Jean-Jacques and Henkel, Carsten}, title = {Rayonnement thermique coh{\´e}rent}, issn = {0290-0041}, year = {2006}, abstract = {Le rayonnement {\´e}lectromagn{\´e}tique produit par un corps {\`a} temp{\´e}rature T est g{\´e}n{\´e}ralement consid{\´e}r{\´e} comme l'exemple type du rayonnement incoh{\´e}rent que l'on oppose au rayonnement laser. L'un est quasi isotrope tandis que l'autre est tr{\`e}s directionnel, l'un a un large spectre tandis que l'autre est quasi-monochromatique. Aussi surprenant que cela puisse para{\^i}tre, le rayonnement thermique de bon nombre de corps est coh{\´e}rent lorsque l'on se place {\`a} une distance inf{\´e}rieure {\`a} la longueur d'onde de la surface {\´e}mettrice. Nous verrons que ces effets peuvent {\^e}tre pr{\´e}dits {\`a} l'aide d'une approche {\´e}lectromagn{\´e}tique du rayonnement thermique. Plusieurs exp{\´e}riences r{\´e}centes ont confirm{\´e} ces propri{\´e}t{\´e}s inattendues.}, language = {fr} } @article{IntravaiaHenkelLambrecht2007, author = {Intravaia, Francesco and Henkel, Carsten and Lambrecht, Astrid}, title = {Role of surface plasmons in the Casimir effect}, year = {2007}, abstract = {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.}, language = {en} } @article{GreffetHenkel2007, author = {Greffet, Jean-Jacques and Henkel, Carsten}, title = {Coherent thermal radiation}, issn = {0010-7514}, year = {2007}, abstract = {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.}, language = {en} } @article{Henkel2007, author = {Henkel, Carsten}, title = {Laser theory in manifest Lindblad form}, issn = {0953-4075}, year = {2007}, abstract = {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.}, language = {en} }