NUM division - Publication Highlights

Magnetoelectric phenomena are intimately linked to relativistic effects and also require the material to break spatial inversion symmetry and time-reversal invariance. Magnetoelectric coupling can substantially affect light–matter interaction and lead to non-reciprocal light propagation. Here, we confirm on a fully experimental basis, without invoking either symmetry-based or material-specific assumptions, that the optical magnetoelectric effect in materials with non-parallel magnetization (M) and electric polarization (P) generates a trilinear term in the refractive index...

We report a new measurement of the n=2 Lamb shift in Muonium. Our result of 1047.2(2.3)_stat(1.1)_syst  MHz comprises an order of magnitude improvement upon the previous best measurement. This value matches ...

The manipulation of topological states in quantum matter is an essential pursuit of fundamental physics and next-generation quantum technology. Here we report the magnetic manipulation of Weyl fermions in the kagome spin-orbit semimetal Co₃Sn₂S₂, observed by high-resolution photoemission spectroscopy. We demonstrate the exchange collapse of spin-orbit-gapped ferromagnetic Weyl loops into paramagnetic Dirac loops under suppression of the magnetic order.

Alzheimers disease is one of the major global health challenges. Neuronal cell dysfunction and death are connected to the self-assembly of the amyloid β peptide (Aβ42) into oligomeric and fibrillar aggregates. The fibril surface can catalyze the formation of toxic oligomers via secondary nucleation.

FeSi is a nonmagnetic narrow-gap insulator, exhibiting peculiar charge and spin dynamics beyond a simple band structure picture. Those unusual features have been attracting renewed attention from topological aspects. Although the surface conduction was demonstrated according to size-dependent resistivity in bulk crystals, its topological characteristics and consequent electromagnetic responses remain elusive. Here, we demonstrate ...

We investigated the superconducting properties of the topological superconductor α-PdBi₂ at ambient and external pressures up to 1.77 GPa using muon spin rotation experiments. The ambient pressure measurements evince a fully gapped s-wave superconducting state in the bulk of the specimen. Alternating current magnetic susceptibility and muon spin rotation measurements manifest a continuous suppression of T_c with increasing pressure.

CrI₃ has raised as an important system to the emergent field of two-dimensional van der Waals magnetic materials. However, it is still unclear why CrI₃ which has a ferromagnetic rhombohedral structure in bulk, changed to anti-ferromagnetic monoclinic at thin layers. Here we show that this behaviour is due to the coexistence of both monoclinic and rhombohedral crystal phases followed by three magnetic transitions at T_C1 = 61 K, T_C2 = 50 K and T_C3 = 25 K.