Experimental journey at the edge of quantum materials

Abstract

Over the last decades, condensed matter physics has been the playground for the realization of physical systems in which quantum effects persist over a wide range of energy and length scales. The resulting quantum materials include topological insulators, topological crystalline insulators, magnetically doped topological quantum materials, 2-dimensional van der Waals (2D vdW) materials, Kitaev- , and spin-orbit-materials. This overview encompasses some of the research results we have achieved on emergent phenomena in quantum materials, prticularly on topology, symmetry, and spin-orbit coupling. Included are: the demonstration of Rashba spin-orbit coupling in wurtzite n-GaN:Si, the discovery of infra-red optically active centres in (Ga,Mn)N:Mg, the electronic characteristics that emerge in the Mn doped topological crystalline insulator SnTe and in the intrinsic ferromagnetic topological insulator Mn(Sb,Bi)2Te4. Moreover, it is shown that the study of 2D topological semimetals has revealed (i) quantum chiral anomaly in flakes of the Weyl semimetal Td-WTe2 up to a record temperature of 100 K, and (ii) Pt vacancy-induced Kondo effect in non-magnetic PtSe2.