Jens Wiebe

Academic Affiliation: University of Hamburg

Research Interests: Scanning Probe Methods

Research stay period: July 23 ~ Aug 12, 2022

Jens Wiebe

Academic Affiliation: University of Hamburg

This lecture is intended for Master and PhD students as well as young Postdocs. After a short historical review of
the discoveries of materials which are conventional and unconventional superconductors, I will give an
introduction to Cooper pairing and the Bardeen–Cooper–Schrieffer (BCS) theory, the microscopic theory for the
description of conventional superconductivity. Then, I will describe the quasiparticle excitation spectrum of such
a superconductor and explain how it can be experimentally measured using scanning tunnel spectroscopy, both
with normal-metal and superconducting tips. Subsequently, I will talk about the effects of magnetic fields and
single magnetic impurities on a superconducting substrate, where the latter leads to the so-called Yu-ShibaRusinov bound states. Finally, I will explain different strategies to tailor a topological superconductor, including
the spin chain platform where bands formed by the hybridization of Yu-Shiba-Rusinov states in chains of magnetic
atoms in contact to a superconducting surface can host Majorana bound states.

Literature

C. Enss and S. Hunklinger, Low Temperature Physics (Springer 2005)
R. Gross and A. Marx, Festkörperphysik (De Gruyter 2014): unfortunately only in german so far…
Several original publications

Yousoo Kim

Academic Affiliation: University of Tokyo

Research interests: Surface Science, Molecular Interface, Scanning Tunneling Microscopy

Youngchan Kim

Academic Affiliation: University of Surrey

Research Interests: Quantum Biology, Biophotonics, FRET, FCS, Anisotropy

Research stay period: Aug 16 ~ Aug 16, 2022

Youngchan Kim

Academic Affiliation: University of Surrey

Title: Quantum biology in fluorescent protein: a new model system to study quantum effects in biology

Abstract:

Quantum effects are usually thought to be too delicate to manifest in biology since random molecular interactions were thought to be instantaneously obliterated quantum coherent molecular interactions occurring in wet biological environments. However, recent biological, chemical, and physical breakthroughs have revealed that subtle quantum effects may shape biological processes and functions, as exemplified by photosynthesis, enzyme catalysed reactions, and magnetic field effects on spin-dependent reactions in biology, to name a few. Studying coherent dipole-dipole coupling between biomolecular systems is challenging but holds many fascinating, fundamental questions that will inspire new ways to better understand and enhance health and medicine. A recent study suggests that the yellow fluorescent proteins, Venus_A206, exhibit room-temperature exciton coupling when they form a dimer. Because cryogenic temperature is not required to observe such quantum effects, genetically engineered fluorescent protein assemblies could inspire a new way towards developing biological quantum technologies, such as quantum-enhanced biosensors. In this talk, I will present the recent progress in studying quantum biology using fluorescent proteins.

Harald Brune

Academic Affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL)

Research Interests: Exploration of the novel physical and chemical properties arising when metals shrink to the nanoscale

Research stay period: Sept 13 ~ Dec 10, 2022