Topological Weyl Semimetals for Spintronic Devices

• Applicants: Professorin Dr. Claudia Felser, since 5/2017; Professor Dr. Stuart Parkin
• Subject Area: Experimental Condensed Matter Physics ; Theoretical Condensed Matter Physics
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314790414

The topological Weyl semimetal (WSM) carries giant Berry curvatures in the momentum space near the Fermi energy, because its conduction and valence bands cross linearly through nodes that are singularity points (source/sink) of the Berry curvature. Considering the large Berry curvatures and strong spin-orbit coupling in a WSM, we propose that a WSM can exhibit a strong intrinsic spin Hall effect (SHE), which is a manifestation of the spin-dependent Berry phase. The SHE can be used to electrically generate or detect spin currents in spintronic devices. These spin currents can, in particular, be used to excite or manipulate magnetic nano-elements and domain walls. We propose to perform both theoretical and experimental investigations of the SHE of the WSM TaP and related compounds that have been discovered recently. We will fabricate and optimize the growth of high quality WSM thin films using two different deposition techniques, evaporation and sputtering. Spintronic devices will be formed from these WSM films by coupling them to various magnetic thin films, guided by the insights of our ab-initio calculations. Our proposed SHE devices will pave the way to room-temperature applications of topological materials. In addition, we will offer WSM thin film samples and single crystals for other SPP collaborators.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1666: Topological Insulators: Materials - Fundamental Properties - Devices
• Co-Investigator: Vicky Süss
• Ehemaliger Antragsteller: Dr. Binghai Yan, until 5/2017