The rise of two-dimensional (2D) materials has ignited a revolution in modern physics. These atomic sheets offer a unique playground for studying transport, optics, and magnetism, where properties can be stacked, strained, and twisted to create entirely new materials not found in nature. By relying on weak but precise van der Waals forces to hold these layers together, we can now engineer electronic behavior at the smallest possible scale. In this talk, I will explore the frontier of two-dimensional Spintronics, a field that aims to transcend the "power wall" of traditional electronics. Instead of simply moving electrical charges, spintronics harnesses the electron's spin to process and store information, promising devices that are faster and more energy-efficient than today’s silicon chips. I will discuss how one can "indoctrinate" a material like graphene with magnetic or spin-orbit properties through the spin proximity effects, where the wavefunction hybridizes with a distinct neighbor to inherit new physical identities. I will present recent experimental and theoretical advances in this spin van der Waals engineering, demonstrating how tunable interfacial interactions can lead to both Hamiltonian engineering to discover fundamental phenomena, but also potential applications.
Superconductivity and the fractional quantum Hall (FQH) effect are two landmark discoveries in modern physics. Superconductivity requires the presence of an effective pairing glue, which seems incompatible with the FQH effect, which requires strong repulsive interactions among electrons. Nevertheless, experiments in two-dimensional materials have recently observed both phases in close proximity to each other. A tantalizing explanation for this interplay is Laughlin's idea of “anyon superconductivity”, which proposes that superconductivity arises from a finite density of anyons — exotic quasiparticles emerging from the FQH state — carrying fractional charge. However, a key question is how Cooper pairing can occur in systems with purely repulsive interactions. I will demonstrate that anyon superconductivity can naturally emerge from an unconventional energy hierarchy of excitations when a missing ingredient is supplied: proximity to a topological phase transition. This provides a microscopic mechanism for anyon superconductivity, and allows us to construct the first controlled model for which low-energy Cooper pairs coexist with a FQH phase. I will present analytical and numerical results which could help guide future experiments and also allow us to describe continuous transitions between FQH states and chiral superconductors.
The plasma composition in the solar corona is variable, with a strong dependency on the first ionisation potential (FIP) of elements. In flaring regions, plasma composition has been shown to have significant spatial and temporal variations, likely driven by dynamical processes triggered by energy release at the reconnection site. The origin of these variations and their impact on flare loop dynamics are not yet fully understood. In this work, we use high cadence Hinode EIS spectroscopic observations of the M-class flare peaking at 13:56 UT on 2 April 2022, alongside simulations from the 0D EBTEL hydrodynamic model, to investigate the role of plasma composition in modulating radiative losses in solar flare loops. We identify two regions along the flare loop arcade, with distinct FIP bias values as well as cooling rates, suggesting that spatial variations in plasma composition may play a key role in influencing flare loop cooling. In this framework, I will also discuss the potential of high resolution spectropolarimetric observations from the upcoming IBIS 2.0 instrument, currently under installation at the THEMIS telescope, particularly for advancing studies of the physical mechanisms driving plasma composition variations, flare dynamics and the coupling between the two.
Um Zukunftsmusik geht es im Vortrag: Mission Vigil - Weltraumwettervorhersage aus einzigartiger Perspektive. 2031 startet die ESA-Raumsonde Vigil ins All. Aus seitlicher Beobachtungsposition wird der Sonnenspäher eher als erdnahe und erdgebundene Teleskope erkennen können, wenn sich auf der Sonne gefährliches Weltraumwetter zusammenbraut. Eines der wissenschaftlichen Instrumente der Mission entsteht derzeit am MPS. Johann Hirzberger vom MPS gibt einen Überblick.
