From topological magnetism to topological superconductivity
Speaker: Dr Roberto Lo Conte (Physics Department, University of Hamburg)
Title: From topological magnetism to topological superconductivity
Abstract: The upcoming revolution in information technology driven by quantum computing has triggered the search for new quantum materials. Hybrid quantum systems, where materials with different properties (magnetism, superconductivity, spin-orbit coupling) are joined together, are expected to host emergent quantum properties such as topological  and triplet  superconductivity, which can be used for the implementation of fault tolerant quantum computing  and the design of ultralow dissipation spintronic devices . In particular, it has been proposed that the combination of topological spin textures - such as magnetic skyrmions - and superconducting materials could lead to the stabilization of topological superconducting states [5,6].
In this talk I will first discuss the stabilization of magnetic skyrmions in thin film multilayers without the requirement of any external magnetic field . This is achieved by tailoring the magnetic properties of multilayers where an interlayer exchange coupling is present between two magnetic layers separated by a non-magnetic spacer. Most importantly, I will explain how, by tailoring the strength of the interlayer coupling, we can tune the size of the stabilized skyrmions. Second, I will discuss our recent investigation of a magnet/superconductor hybrid system consisting of a Mn ultrathin film deposited on top of a superconducting Nb substrate. Our results  show an antiferromagnetic order in the Mn thin film which coexists with a proximity-induced superconducting state. Preliminary spectroscopic data suggest that the hybrid system hosts in-gap Yu-Shiba-Rusinov bands [9,10], which could potentially establish topologically protected Majorana modes.
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