Dr. Stephan Dürr
Stephan Dürr
Telefon: +49 89 3 29 05 - 291
Raum: A 2.22
Prof. Dr. Thomas Udem
Thomas Udem
Telefon: +49 89 3 29 05 - 282 // -257
Raum: D 0.21 // D 0.39

kommende Kolloquien



Die Gastvorträge im Rahmen des MPQ-Kolloquiums finden von April bis Juli sowie von Oktober bis Januar jeweils dienstags um 14:30 Uhr statt.

Achtung! Ab Oktober 2017 finden die Vorträge, aufgrund der Bauarbeiten, vorübergehend im Interims-Hörsaal, Raum B 0.32 am Max-Planck-Instituts für Quantenoptik statt.

Ansprechpartner für die wissenschaftliche Organisation:

Dr. Stephan Dürr und Dr. Thomas Udem

Wenn Sie einen Vortrag im Livestream verfolgen möchten, ist es nötig, dass Sie sich in eine entsprechende Mailing Liste eintragen. Daraufhin erhalten Sie Instruktionen zum Empfang des Livestreams.


"Recent experiments with ions on microfabricated surface traps."

"In this talk I will report on recent progress made at NIST Boulder in the manipulation of ions using microfabricated surface traps. A first experiment performs a laser-less two qubit logic gate, taking advantage of the high magnetic field gradients that can be generated on ion chips. A second experiment, operated at cryogenic temperature, shows the exchange of a single quantum of vibration between two ions trapped 40 micrometers apart. Lastly, I will describe an experiment where the anomalous heating rate of a trapped ion is reduced by a factor of 100 after in-situ cleaning of the surface of the trap." [mehr]

"Fundamental physics with ultra-cold neutrons at the FRM-2."

"Ultra-cold neutrons (UCN) are a unique tool to measure fundamental properties of nature. Due to the neutron’s comparably simple composition, it is also a favored system to perform searches for a permanent electric dipole moment (EDM) of a fundamental system that violates time reversal symmetry. Such a phenomenon is required in most theories in particle physics to explain the excess of matter versus antimatter in the Universe, a problem which the standard model of particle physics fails to explain by eight orders of magnitude. The search for EDMs is already ongoing for many years in different systems and has already ruled out or restricted many theories and already probes energy scales beyond the LHC. In this talk I will give an overview of the research with such very slow neutrons and focus on a new flagship experiment that is currently being set up at the FRM-2 reactor in Garching to measure the neutron EDM with a sensitivity of 10-28 This corresponds to a larger than a factor 100 improvement, which requires next to the strongest possible source of UCN also an elaborate effort to control systematic effects in small magnetic and electric fields." [mehr]

"Ultrahigh plasma acceleration by lasers possibly for nuclear energy without dangerous radiation."

"Sauerbrey’s measurement [1] of ultrahigh acceleration of plasma blocks by 1020 cm/s2 with ps laser pulses at very high intensity – confirmed by Földes et al. [2] – are 10,000 times higher than any acceleration with ns laser pulses. At ns, thermal pressure with losses and delays dominates the interaction, while the ps case is dominated by the instantly acting nonlinear (ponderomotive) force. The ps acceleration of 1020 cm/s2 was theoretically and numerically predicted in 1978 [3] (see p. 179). The mechanism is different from acceleration of ion beams due to relativistic self-focusing which has to be avoided using very high contrast ratio laser pulses. Based on the measurements [1,2] the mechanism of the ps acceleration in contrast to that with ns pulses can now be understood as the non-thermal >99% efficient transfer of optical energy into macroscopic motion of the irradiated electron cloud in the space charge neutral plasma, where the inertia is determined by the cloud of the attracted ions. After this plasma block acceleration has been clarified by several further measurements [4], this can be applied to the picosecond irradiation of uncompressed solid DT fusion fuel by side-on igniton [5] of a fusion flame. Computations for igniting solid density hydrogen-boron(11) is only less than 10 times more difficult and may lead to fusion energy production with less radioactivity than from burning coal [6]." [1] Sauerbrey R. Physics of Plasmas 3: 4712 (1996)[2] Földes I B, Bakos J S, Gal, K. et al. Laser Physics 10: 264 (2000)[3] Hora H Physics of Laser Driven Plasmas. New York: John Wiley 1981[4] Hora H., Badziak J., Jie Zhang, K. Jungwirth, K. Rohlena et al. Physics of Plasmas 14: 072701 (2007)[5] Hora H, Miley G H, Flippo K, Lalousis P et al. Laser and Particle Beams 29, 353 (2011)[6] Hora H, Miley G H, He X. et al.2010 Energy and Environmental Science 3: 479 (2010)[7] Hora H, Miley, G H, Yang X., Lalousis P. Astrophysics and Space Science 336: 225 (2011) [mehr]

"High power laser research at the Townes Institute, ultrafast lasers and all."

"The seminar will describe latest work in high power fiber and solid state laser development, new investments in next generation lasers, high power OPCPA single cycle laser development, and some applications. It will also summarize the continuing build out of the Townes Laser Institute." [mehr]

"Recent developments in atomic and diamond magnetometers and their applications in NMR."

"A lot is going on in the magnetometry field, with new techniques sprouting that allow ever-improved sensitivity and spatial resolution. One of the latest raves is magnetometers based on color centers in diamond that consist of a substitutional nitrogen atom and a vacancy in a diamond lattice.To measure Earth’s magnetic field, an orange laser beam is directed at a layer of sodium 90 kilometers above the planet. This presentation will cover recent applications of magnetometers to nuclear magnetic resonance without magnets (!) and other magnetometer adventures ranging from the search for plant biomagnetism to measuring magnetic fields in the mesosphere using sodium laser guide stars." [mehr]

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