Michael Fischer

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Close to realistic responses to anti-cancer drugs are not adequately provided in monolayer or single cells assays. 3-dimensional multicellular cultures (spheroids) mimicking in vivo-like conditions are established as cell biological models for microtumors/metastases. For a non-invasive real-time monitoring of the electrical parameters of such spheroid(More)
We have applied an optical method to the measurement of the 2S hyperfine interval in atomic hydrogen. The interval has been measured by means of two-photon spectroscopy of the 1S-2S transition on a hydrogen atomic beam shielded from external magnetic fields. The measured value of the 2S hyperfine interval is equal to 177 556 860(16) Hz and represents the(More)
Multicellular tumour spheroids that mimic a native cellular environment are widely used as model systems for drug testing. To study drug effects on three-dimensional cultures in real-time we designed and fabricated a novel type of sensor chip for fast, non-destructive impedance spectroscopy and extracellular recording. Precultured spheroids are trapped(More)
We have remeasured the absolute 1S-2S transition frequency nu(H) in atomic hydrogen. A comparison with the result of the previous measurement performed in 1999 sets a limit of (-29+/-57) Hz for the drift of nu(H) with respect to the ground state hyperfine splitting nu(Cs) in 133Cs. Combining this result with the recently published optical transition(More)
Precision spectroscopy of the simple hydrogen atom has inspired dramatic advances in optical frequency metrology: femtosecond laser optical frequency comb synthesizers have revolutionized the precise measurement of optical frequencies, and they provide a reliable clock mechanism for optical atomic clocks. Precision spectroscopy of the hydrogen 1S-2S(More)
Displacement of propagating quantum states of light is a fundamental operation for quantum communication. It enables fundamental studies on macroscopic quantum coherence and plays an important role in quantum teleportation protocols with continuous variables. In our experiments, we have successfully implemented this operation for propagating squeezed(More)
We realize tunable coupling between two superconducting transmission line resonators. The coupling is mediated by a non-hysteretic rf SQUID acting as a flux-tunable mutual inductance between the resonators. We present a spectroscopic characterization of the device. In particular, we observe couplings g/2π ranging between –320 MHz and 37 MHz. In the case of(More)
We calculate the full O(αs) radiative corrections to the three spin independent and five spin dependent structure functions that describe the angular decay distribution in the decay of a polarized top quark into a W -boson (followed by the decay W+ → l+ + νl or by W + → q̄ + q) and a bottom quark. The angular decay distribution is described in cascade(More)
The balloon-borne Millimeter-Wave Anisotropy Experiment (MAX) is designed to measure the fluctuations in the cosmic microwave background (CMB) on angular scales from 0.3 to several degrees. The long term goal is to measure many pixels on the sky at a level appr~ching AT/T(CMB) = 1 x 10e6. These angular scales fill an important gap between the angular scales(More)
N. Kolachevsky, M. Haas, U. D. Jentschura, M. Herrmann, P. Fendel, M. Fischer, R. Holzwarth, Th. Udem, C. H. Keitel, and T. W. Hänsch Max–Planck–Institut für Quantenoptik, Hans–Kopfermann–Str. 1, 85748 Garching, Germany P.N. Lebedev Physics Institute, Leninsky prosp. 53, 119991 Moscow, Russia Max–Planck–Institut für Kernphysik, Saupfercheckweg 1, 69117(More)