Thema:

Enhancing the sensitivity of phase microscopy

Datum:

06.12.21

Uhrzeit:

16:15

Ort:

H4

Vortragender:

Dr. Thomas Juffmann

University of Vienna

Inhalt:

Optical phase contrast microscopy and cryo-electron microscopy are widely used in the study of cells and proteins, respectively. In both techniques, a specimen imparts a phase shift on the probe (photons or electrons), which can be measured using various interferometric techniques. In this talk I will briefly discuss the physical basics and limits of phase microscopy, and will show ways how to improve on current techniques using wave-front shaping, cavity or quantum enhanced measurements. I will demonstrate how wave-front shaping can enable phase contrast imaging with optimized sensitivity, and how multi-passing the probe particles through a sample can be used for high sensitivity / low damage imaging. The latter could potentially allow for cryo-electron microscopy with unprecedented resolution. Finally, I will discuss how one of the techniques we developed can be used for gating images on the nanosecond scale, which enables video-rate fluorescence lifetime imaging with single molecule sensitivity.

Ansprechpartner:

T. Huser

Thema:

20220506-Volker Bach-TBC

Datum:

06.05.22

Uhrzeit:

16:15

Ort:

ZOOM/Konferenzschaltung

Vortragender:

Volker Bach

Technische Universität Braunschweig

Inhalt:

TBC

Ansprechpartner:

M. Baake

Thema:

Large Scale Structure and Integrated Sachs-Wolfe Effect Measurements with the Rapid ASKAP Continuum Survey

Datum:

13.01.22

Uhrzeit:

15:36

Ort:

D6-135

Vortragender:

Benedict Bahr-Kalus

Korea Astronomy and Space Science Institute, KASI

Inhalt:

Ansprechpartner:

D. Schwarz

Thema:

tba

Datum:

14.01.22

Uhrzeit:

14:15

Ort:

D5-153

Vortragender:

Roman Rausch

TU Braunschweig

Inhalt:

Ansprechpartner:

Jürgen Schnack

Thema:

On Non-Hermitian Beta-Ensembles

Datum:

14.10.21

Uhrzeit:

16:00

Ort:

D5-153

Vortragender:

Patricia Päßler

Universität Bielefeld

Inhalt:

Log-gases with inverse temperature beta are systems with many applications in physics, for example in the theory of superconductors or the fractional quantum Hall effect. For some specific values of beta a correspondence to random matrix theory (RMT) is well established. The advantage of this connection is the usage of the RMT methods in the study of those systems. The goal of this talk is the discussion of Log-gases in two dimensions, i.e. in the non-Hermitian case, for more general values of the inverse temperature. Therefore, we study in the first part a model of normal 2 × 2 matrices with beta in [0,2] and discuss whether we find a surmise for the nearest-neighbour spacing distribution of large matrices. In the second part of the talk we introduce the study of symmetry classes in non-Hermitian RMT. We conjecture that the classes of complex symmetric and complex quaternion matrices can be effectively described by Log-gases in two dimensions with non-integer inverse temperatures.

Ansprechpartner:

Gernot Akemann

Thema:

Color-Flavor Transformation Revisited

Datum:

01.12.21

Uhrzeit:

09:00

Ort:

ZOOM / Konferenzschaltung

Vortragender:

Martin Zirnbauer

Universität Köln

Inhalt:

The "color-flavor transformation", conceived as a kind of generalized Hubbard-Stratonovich transformation, is a variant of the Wegner-Efetov supermatrix method for disordered electron systems. Tailored to quantum systems with disorder distributed according to the Haar measure of a compact Lie group of any classical type (A, B, C, or D), it has been applied to Dyson's Circular Ensembles, random-link network models, quantum chaotic graphs, disordered Floquet dynamics, and more. We review the method and, in particular, explore its limits of validity. We also sketch a new alternative method to treat models where the color-flavor transformation fails.

Ansprechpartner:

Mario Kieburg