Novel Quantum Phases in Superconducting Heterostructures

769. WE-Heraeus-Seminar

30 May - 02 Jun 2022


Physikzentrum Bad Honnef

Scientific organizers:

Prof. Dr. Elke Scheer, Prof. Dr. Wolfgang Belzig, Universität Konstanz • Prof. Dr. Christoph Strunk, Universität Regensburg

The phenomenon of superconductivity is a central element in the development of novel quantum technologies. On the one hand, the most elementary quantum units are realized, investigated and manipulated in superconducting heterostructures, while on the other hand superconducting detection technologies explore the ultimate limits. Novel superconducting materials, such as two-dimensional crystals or synthetic magnet-superconductor compounds, illustrate the enormous possibilities that are currently being explored. The resulting novel quantum phases are characterized using the full range of experimental techniques, from scanning tunneling spectroscopy, to transport properties, as well as in their magnetic response. Accompanied by theories using state-of-the-art nonequilibrium quantum field theory methods, a synergistic progress towards new insights and applications is emerging.

Quantum technologies are shaping today's modern solid-state physics and motivate to construct, study, characterize, and control novel quantum phases. For example, two-dimensional van der Waals heterostructures are assembled from an almost infinite variety of two-dimensional crystals, giving rise to synthetic materials that exhibit properties not found in single layers. A recent example is twisted bi-layer graphene with specific angles creating moiré superstructures with flat bands and unique correlated phases. Magnetic crystals can be used to introduce either a ferromagnetic, an antiferromagnetic, or even noncollinear magnetic order into a two-dimensional superconductor enabling new pairing states and spin-polarized supercurrents. Spin-orbit coupling can control fundamental pairing mechanisms and produce unusual Ising superconductivity. In general, strong spin-orbit coupling at interfaces produces novel superconducting phases characterized, e. g., by a paramagnetic Meissner response. These effects have recently been experimentally unveiled by sophisticated methods.

The conference language will be English. The Wilhelm and Else Heraeus-Foundation bears the cost of full-board accommodation for all participants.