Stuart Parkin1
Max Planck Institute of Microstructure Physics1
Stuart Parkin1
Max Planck Institute of Microstructure Physics1
Van der waal’s structures provide for many opportunities for breaking symmetry. We show that the presence of topological chiral spin textures in both Fe<sub>3</sub>GeTe<sub>2</sub><sup>1</sup> and and Cr<sub>1+δ</sub>Te<sub>2 </sub>(δ ≈ 0.3)<sup>2</sup>, namely Néel skyrmions, is the result of a lowering of their nominally centrosymmetric structures. High resolution x-ray diffraction from thin lamellae of these compounds shows an asymmetric distribution of Fe vacancies in the former and in the latter a superstructure formed by Te atoms within the vdw gaps. On the other hand we show non-reciprocal superconducting properties in Josephson junctions formed by proximitizing the van der Waals compound NiTe<sub>2 </sub>using superconducting electrodes formed from niobium electrodes<sup>3</sup>. We discuss proximity induced superconductivity in several other van der Waals materials that show evidence for intrinsic time reversal symmetry breaking.<br/><br/>1 Chakraborty, A.<i> et al.</i> Magnetic skyrmions in a thickness tunable 2D ferromagnet from a defect driven Dzyaloshinskii-Moriya interaction. <i>under review</i> (2021).<br/>2 Saha, R.<i> et al.</i> Observation of Néel-type skyrmions in acentric self-intercalated Cr<sub>1+δ</sub>Te<sub>2</sub>. <i>Nat. Commun.</i> <b>13</b>, 3965 (2022).<br/>3 Pal, B.<i> et al.</i> Josephson diode effect from Cooper pair momentum in a topological semimetal. <i>Nat. Phys.</i> <b>online</b> (2022).