Philipp Schneeweiss

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The spin of light in subwavelength-diameter waveguides can be orthogonal to the propagation direction of the photons because of the strong transverse confinement. This transverse spin changes sign when the direction of propagation is reversed. Using this effect, we demonstrate the directional spontaneous emission of photons by laser-trapped caesium atoms(More)
We experimentally study the ground state coherence properties of cesium atoms in a nanofiber-based two-color dipole trap, localized ∼ 200 nm away from the fiber surface. Using microwave radiation to coherently drive the clock transition, we record Ramsey fringes as well as spin echo signals and infer a reversible dephasing time of T(2)(*) = 0.6 ms and an(More)
Advanced photonic nanostructures are currently revolutionizing the optics and photonics that underpin applications ranging from light technology to quantum-information processing. The strong light confinement in these structures can lock the local polarization of the light to its propagation direction, leading to propagation-direction-dependent emission,(More)
Scanning probe microscopes are widely used to study surfaces with atomic resolution in many areas of nanoscience. Ultracold atomic gases trapped in electromagnetic potentials can be used to study electromagnetic interactions between the atoms and nearby surfaces in chip-based systems. Here we demonstrate a new type of scanning probe microscope that combines(More)
Dispersion forces are long-range interactions between polarizable objects that arise from fluctuations in the electromagnetic field between them. Dispersion forces have been observed between microscopic objects such as atoms and molecules (the van der Waals interaction), between macroscopic objects (the Casimir interaction) and between an atom and a(More)
We experimentally realize an optical fiber ring resonator that includes a tapered section with a subwavelength-diameter waist. In this section, the guided light exhibits a significant evanescent field which allows for efficient interfacing with optical emitters. A commercial tunable fiber beam splitter provides simple and robust coupling to the resonator.(More)
Experiments with electron or ion matter waves require a coherent, monochromatic and long-term stable source with high brightness. These requirements are best fulfilled by single atom tip (SAT) field emitters. The performance of an iridium covered W(111) SAT is demonstrated and analyzed for electrons in a biprism interferometer. Furthermore we characterize(More)
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