Ort / Place
Physik Campus Riedberg, Max-von-Laue-Str. 1, 60438 Frankfurt
Großer Hörsaal, Raum 0.111

Zeit / Time
Mittwochs / Wednesday , 16.00 Uhr c.t.
 

11.04.2018      

 

Dr. Stefan Gillessen
Max-Planck-Institut für extraterrestrische Physik, Garching

The Galactic Center: A unique astrophysical laboratory

 25.04.2018

Prof. Werner Maurer Zürcher
Hochschule Winterthur, Schweiz

Physik der dynamischen Systeme (Systemphysik)

30.05.2018

Dr. Hendrik van Hees
Institut für Theoretische Physik, Goethe-Universität Frankfurt
Antrittsvorlesung

Dileptons and photons Messengers from strongly interacting matter under extreme conditions from the hot and dense state

06.06.2018

Prof. Dr. Andrea Markelz
Department of Physics, University at Buffalo, SUNY, Buffalo,  USA
Adjunct Professor, Department of Structural Biology, University at Buffalo, SUNY, Buffalo, USA
Visiting Professor, Department of Physics, Univeristat, Regensburg, Germany

Terahertz Light Fingerprints Biomolecular Dynamics

13.06.2018

Prof. Dr. Vladimir Falko
National Graphene Institute University of Manchester Manchester, UK

Moiré superlattices and magnetic minibands in graphene heterostructures
When graphene lattice is aligned with the hBN lattice, a long-wavelength periodic moiré pattern forms due to a weak incommensurability of the two lattice structures, leading to a long-range superlattice affecting properties of electrons in graphene, including formation of miniband spectra for Dirac electrons and reappearance of magnetic minibands at the rational values of magnetic field flux through the supercell area (in units of ϕ0=h/e), also known as Hofstadter butterfly.
Here, we show that the quantum effect of the minibands formation in long-period moiré superlattices (mSL) in graphene/hBN heterostructures affect their transport measurements up to the room temperature. In relation to the low-field behavior, we find that the overall temperature dependence of resistivity displays the opening in a new scattering process: the umklapp electron-electron scattering in which two electrons coherently transfer the mSL Bragg momentum to the crystal. The formation magnetic minbands and their manifestation in magneto-oscillation of the diagonal conductivity tensor persist up to the room temperature, too, with full hierarchy of features that are attributed to the rational flux values ϕ=(p/q)ϕ0, with p=1, 2 and up to 3 (and 7<q<1), now, observed at the intermediate range of 50K<T<200K.

20.06.2018

Prof. Dr. Klaus Blaum
Max-Planck-Institut für Kernphysik Heidelberg

Precision Experiments with Stored and Cooled Ions

An overview is given on recent measurements with extreme precision on single or few cooled ions stored in Penning traps. On the one hand, mass measurements provide crucial information for atomic, nuclear and neutrino physics as well as for testing fundamental symmetries. On the other hand, g-factor measurements of the bound electron in highly-charged hydrogen-like ions allow for the determination of fundamental constants and for constraining Quantum Electrodynamics. For example, the most stringent test of CPT symmetry in the baryonic sector could be performed by mass comparison of the antiproton with H- and the knowledge of the electron atomic mass could be improved by a factor of 13.


27.06.2018

Dr. Nadine Schwierz-Neumann
Emmy Noether Nachwuchsgruppenleiterin Max-Planck-Institut für Biophysik Frankfurt

Metal cations and RNA - a highly charged problem with a dynamic future

Ribonucleic acid (RNA) is one of the most diverse biomolecules on Earth. RNA molecules are much more than information carriers between the DNA and the proteins. They play key roles in every vital process including protein synthesis and transport or gene expression. However, RNA molecules are highly charged polymers. Therefore, they can only fold into a compact and functional structure in the presence of positively charged ions. Our research focuses on the role of metal cations in the folding and function of RNA. Resolving the role of metal cations is challenging experimentally since the resolution is typically insufficient to characterize the exact interactions. Here, computational methods such as molecular dynamics simulations can contribute significant insight. However, these simulations are challenged by the fact that they have to cover a broad spectrum of time scales ranging from femtoseconds to minutes and hours. As a way to quantitatively describe cation-RNA interactions, I will discuss optimized atomistic models for the metal cations. These optimized models in combination with advanced sampling techniques allow us to resolve ion specific effects and to gain atomistic insight into the kinetics of cation binding. Subsequently, I will discuss the role of different metal cations in systems of increasing complexity starting from small structural RNA motifs and ranging to large and biologically relevant RNA macromolecules.

 

04.07.2018

Prof. Dr. Hartmut Wittig              
Institut für Kernphysik, Johannes Gutenberg-Universität Mainz

The limits of the Standard Model and the role of Lattice QCD

The particle content of the Standard Model has been completely established following the discovery of the Higgs boson.  While the Standard Model describes all known phenomena in accelerator-based experiments, it leaves many important questions unanswered: what is the reason for the large asymmetry between the abundance of matter and anti-matter? What is the nature of dark matter? In this talk I describe several attempts to detect signals for physics beyond the Standard Model using precision experiments at low energies. Furthermore, I discuss the role of lattice Quantum Chromodynamics for these efforts. 

11.07.2018

Prof. Dr. Werner Mäntele
Institut für Biophysik, Goethe-Universität Frankfurt
-A b s c h i e d s v o r l e s u n g-
Bioanalytical Infrared Spectroscopy: Quo vadis ?

Infrared (IR) spectroscopy has long been established as a routine analytical technique in chemistry, but applications for biological samples seemed impossible due to instrumental limitations such as low emissivity of thermal sources and long recording times. In addition, water as a strong absorber prevented “real” biological samples from being analysed. The introduction of Fourier transform IR (FT-IR) techniques in the 80’s marks the first milestone for bioanalytical IR spectroscopy, and new techniques for the preparation of biological samples led to a rapidly growing field. FT-IR techniques are since used, as reaction-modulated difference techniques, for the analysis of biopolymers, complemented by ultrafast laser techniques. Our community has since then learnt to track and analyse individual bonds in macromolecules, their dynamics and their reactivity, from picoseconds to seconds or minutes. IR spectroscopy is now an established technique complementing structure analysis e.g. by X-ray crystallography or 2-D-NMR spectroscopy.
The advent of quantum cascade lasers (QCL) in the late nineties, powerful narrow-band single wavelength IR emitters, multi-wavelength sources, or, with an external cavity (EC), tunable EC-QCLs presents a further milestone in bioanalytical IR spectroscopy. Their power reaches to hundreds of mW and their tunability can extend over several 100 cm-1, sufficiently broad to scan the entire IR fingerprint region within some msec. This opened IR spectroscopy for biomedical applications ex vivo and in vivo, for sensors and mobile devices.
The lecture presents bioanalytical and biomedical applications of IR technology at some typical examples. We will start from earlier work on the structure, function and dynamics of proteins an move to most recent developments for the analysis of body fluids in vitro and skin parameters in vivo.

18.07.2018

Nobelpreisträger
Prof. Dr. Joachim Frank
Frank Lab Columbia University New York, USA

The future of cryo-EM

Now that close-to-atomic resolution can be reached almost routinely in many cases, single-particle cryo-EM is about to fill a large gap in the structural database, and this will have a significant impact on the war chest of Molecular Medicine. In terms of future developments I'd like to single out two promising directions:  time-resolved cryo-EM (the ability to image short-lived states), and mapping of a continuum of states of a molecule (especially molecular machines) in a system in equilibrium. 

Rückblick Physikalisches Kolloquium:
SS 2010, WS 2010/11, SS 2011, WS 2011/12, SS 2012, WS 2012/13, SS 2013, WS 2013/14, SS 2014, WS2014/15, SS2015, WS2015/16, SS2016, WS2016/17, SS 2017, WS 2017/18