Wydarzenia w AGH

Wykład zatytułowany Linear and nonlinear spin and charge transport in topological insulators and van-der-Waals heterostructures: towards van-der-Waals electronics wygłosi dr hab. Anna Dyrdał, prof. UAM (Uniwersytet im. Adama Mickiewicza w Poznaniu, Wydział Fizyki, Zakład Fizyki Mezoskopowej, Instytut Spintroniki i Informacji Kwantowej ISQI).

Udział

• stacjonarny: ACMiN (ul. Kawiory 30, bud. D-16, sala 1.02A)
• zdalny: platforma MS Teams (link)

Streszczenie

Spin-orbit interaction leads to various novel states and phases of matter, like chiral spin textures or interfacial and surface spin-polarized states. It also gives a unique possibility of pure electrical control of the spin degree of freedom, which is of great practical importance. Consequently, the spin-orbit driven phenomena, like for instance the spin Hall effect and current-induced spin polarization, are of particular interest as on one side they reveal fundamental aspects of solid-state physics and on the other side have great potential for practical applications in spintronics and nanoelectronics.

During the seminar, I will focus on spin-to-charge conversion and magnetotransport effects in topological insulators and in two-dimensional (2D) van-der-Waals materials. At the beginning, I will present recent results on van-der-Waals graphene-based and topological-insulator-based heterostructures, and on 2D magnets like Cr-based trihalides. I will show that properties of van-der-Waals systems can be easily tuned externally by gating, twisting, strain, proximity effects, or external magnetic field. All this offers the possibility to enhance and control spin-dependent transport (e.g., anomalous, spin and valley Hall effects, current-induced spin polarization, spin-orbit torques) and also to observe topological phase transitions. In the second part of the seminar, I will briefly discuss recent concepts related to nonlinear magnetotransport. In particular, I will present physical mechanism of nonlinear Hall effect based by the Berry-curvature-dipole, and also mechanisms of bilinear magnetoresistance. Finally, I will show how to determine the strength of spin-orbit coupling from the analysis of bilinear response in the angle-dependent magnetotransport experiments.