Integrated Calendar

We present a novel technique to image superparamagnetic iron oxide nanoparticles via their fluctuating magnetic fields. The detection is based on the nitrogen-vacancy (NV) color center in diamond, which allows optically detected magnetic resonance (ODMR) measurements on its electron spin structure. In combination with an atomic-force-microscope, this atomic-sized color center maps ambient magnetic fields in a wide frequency range from DC up to several GHz [1], while retaining a high spatial resolution in the sub-nanometer range
[2]. We demonstrate imaging of single 10 nm sized magnetite nanoparticles using this spin noise detection technique. By fitting simulations (Ornstein-Uhlenbeck process) to the data, we are able to infer additional information on such a particle and its dynamics, like the attempt frequency and the anisotropy constant [3]. This is of high interest to the proposed application of magnetite nanoparticles as an alternative MRI contrast agent or to the field of particle-aided tumor hyperthermia.

"Deviations of the top electroweak couplings from their Standard Model values imply that certain scattering amplitudes of third generation fermions and longitudinally polarized vector bosons and/or Higgses grow with energy. In this talk I will demonstrate how to use the high energies accessible at the LHC to enhance the sensitivity to non-standard top-Z couplings, which are currently very weakly constrained. I demonstrate the effectiveness of the approach by performing a detailed analysis of tW -> tW scattering, which can be probed at the LHC via pp -> ttWj. I will also present other scattering processes in the same class that could provide further tests of the top sector."

Super-resolution fluorescence microscopy has revolutionized the field of cellular imaging in recent years. Methods based on sequential localization of point emitters (e.g. PALM, STORM) enable imaging and spatial tracking at ~10-40 nm resolution, using visible light. Moreover, three dimensional (3D) tracking and imaging is made possible by various techniques, prominent among them being point-spread-function (PSF) engineering. The PSF of a microscope, namely, the shape that a point source creates in the image plane, can be modified to encode the depth
(z position) of the source. This is achieved by shaping the wavefront of the light emitted from the sample, using spatial phase modulation in the pupil (Fourier) plane of the microscope.
In this talk, I will describe how our search for the optimal PSF for 3D localization, using tools from information theory, led to the development of microscopy systems with unprecedented capabilities in terms of depth of field and spectral discrimination. Such methods enable fast, precise, non-destructive localization in thick samples and in multicolor; we have applied them to super-resolution imaging, tracking biomolecules in living cells and microfluidic flow profiling. Super localization microscopy holds great promise as a uniquely powerful tool for measuring nano-scale dynamics.