Talks

coffee, tea, cookies at 16:00 in the main hall
Monday 16:30-17:30
Seminar room 1+2
- monthly seminars -
Wednesday 15:30 - 17:00
Seminar room 4
- weekly seminars -
Monday 11:00-12:00
Seminar room 4
Wednesday 16:30 - 17:30
Seminar room 1D1
Thursday 14:00-15:00
Seminar room 4

 

 

Vorträge in chronologischer Reihenfolge

27 May 2024
04:30 PM

Colloquium: High order van Hove singularities meet flat bands

Prof. Joseph Betouras (Loughborough University)

Seminarroom 1+2+3 iCal Event
29 May 2024
02:00 PM

Plastic life: What polymer physics can teach us about disordered proteins

Arash Nikoubashman (Leibniz Institute of Polymer Research Dresden)

The discovery of intrinsically disordered proteins (IDPs) has heralded a paradigm shift in molecular biology away from the principle of ”form follows function”. These IDPs can form biomolecular condensates that fulfill numerous functions in living cells, e.g., signal transduction, stress response and controlled reactions. Due to the conceptual similarities between IDPs and classical polymers, physics-based theories and computer simulations can help to understand, predict and engineer the static and dynamic properties of naturally occurring and synthetic IDPs. In this talk, I will present selected insights we have gained from coarse-grained molecular simulations, and discuss the intricacies and limitations of the underlying models. Key findings include that IDPs inherently exhibit heterogeneous interactions that are weak and distributed along the chain contour, and that IDPs collapse at the condensate-water interface and are tangentially oriented. Further, we discovered that the phase behavior and materials properties of condensates can be deducted with great accuracy from the conformations of single IDP chains in solution.

Seminarroom 4 iCal Event
30 May 2024
02:00 PM

Resonant diffusion of a gravitactic circle swimmer

Thomas Franosch (University of Innsbruck)

We investigate the dynamics of a single chiral active particle subject to an external torque due to the presence of a gravitational field -- coined gravitaxis in Ref. [1]. Our computer simulations reveal an arbitrarily strong increase of the long-time diffusivity of the gravitactic agent when the external torque approaches the intrinsic angular drift. We provide analytic expressions for the mean-square displacement in terms of eigenfunctions and eigenvalues of the noisy-driven-pendulum problem. The pronounced maximum in the diffusivity is then rationalized by the vanishing of the lowest eigenvalues of the Fokker-Planck equation for the angular motion as the rotational diffusion decreases and the underlying classical bifurcation is approached. A simple harmonic-oscillator picture for the barrier-dominated motion provides a quantitative description for the onset of the resonance while its range of validity is determined by the crossover to a critical-fluctuation-dominated regime [2]. [1] B. ten Hagen, F. Kümmel, R. Wittkowski, D. Takagi, H. Löwen, and C. Bechinger, Gravitaxis of asymmetric self-propelled colloidal particles, Nature Communications 5, 4829 (2014). [2] O. Chepizhko and T. Franosch, Resonant Diffusion of a Gravitactic Circle Swimmer, Phys. Rev.Lett. 129, 228003 (2022).

Room 1D1 iCal Event
05 Jun 2024
02:00 PM

Title t. b. a.

Suropriya Saha (Max Planck Institute for Dynamics and Self-Organization, Göttingen)

Seminarroom 4 iCal Event
12 Jun 2024
02:00 PM

Title t. b. a.

Shervin Safavi (Faculty of Medicine, TU Dresden)

Seminarroom 4 iCal Event
13 Jun 2024
04:30 PM

QDS

Dr. Clara Wanjura (MPI for the Physics of Light, Erlangen)

Room 1D1 iCal Event
17 Jun 2024
04:30 PM

Colloquium: Lighting up Superconductivity

Prof. Eugene Demler (ETH Zurich)

t.b.a.

Seminarroom 1+2+3 iCal Event
24 Jun 2024
04:30 PM

Colloquium

Seminarroom 1+2+3 iCal Event
27 Jun 2024
04:30 PM

QDS

Dr. Matthias Kübel (Friedrich Schiller University, Jena)

Room 1D1 iCal Event
01 Jul 2024
04:30 PM

t.b.a.

Prof. Erwin Frey (LMU Munich)

Seminarroom 1+2+3 iCal Event
03 Jul 2024
02:00 PM

Title t. b. a.

Robert Großmann (University of Potsdam)

Seminarroom 4 iCal Event
25 Jul 2024
04:30 PM

QDS: Can quantum computing enhance machine learning and, if yes, how?

Prof. Dr. Romas Krems (The University of British Columbia (Vancouver))

I will begin by demonstrating that the answer to the first question in the title is yes [1], in principle. I will then discuss if the quantum advantage of quantum machine learning can be exploited in practice. To discuss how to build optimal quantum machine learning models, I will describe our recent work [2-3] on applications of classical Bayesian machine learning for quantum predictions by extrapolation. In particular, I will show that machine learning models can be designed to learn from observables in one quantum phase and make predictions of phase transitions as well as system properties in other phases. I will also show that machine learning models can be designed to learn from data in a lower-dimensional Hilbert space to make predictions for quantum systems living in higher-dimensional Hilbert spaces. I will then demonstrate that the same Bayesian algorithm can be extended to design gate sequences of a quantum computer that produce performant quantum kernels for data-starved classification tasks [4]. [1] J. Jäger and R. V. Krems, Universal expressiveness of variational quantum classifiers and quantum kernels for support vector machines, Nature Communications 14, 576 (2023) [2] R. A. Vargas-Hernandez, J. Sous, M. Berciu, and R. V. Krems, Extrapolating quantum observables with machine learning: Inferring multiple phase transitions from properties of a single phase, Physical Review Letters 121, 255702 (2018) [3] P. Kairon, J. Sous, M. Berciu and R. V. Krems, Extrapolation of polaron properties to low phonon frequencies by Bayesian machine learning, Phys. Rev. B 109, 144523 (2024). [4] E. Torabian and R. V. Krems, Compositional optimization of quantum circuits for quantum kernels of support vector machines, Physical Review Research 5, 013211 (2023)

Room 1D1 iCal Event
14 Aug 2024
03:30 PM

IMPRS Seminar

tba (tba)

Seminarroom 4 iCal Event
14 Aug 2024
04:45 PM

IMPRS Seminar

Jan Postulka (UCT Prague)

Seminarroom 4 iCal Event
19 Aug 2024
04:30 PM

Colloquium

Seminarroom 1+2+3 iCal Event