Előadó: Rózsa Levente (MTA Wigner FK SZFI)
Előadás címe: " Noncollinear spin configurations in ultrathin magnetic films"
Időpont: 2017. szeptember 19. kedd de. 10:00 óra
Helyszín: MTA Wigner FK I.ép. Tanácsterem
Kivonat:
Noncollinear spin configurations such as chiral domain walls, spin spirals and magnetic skyrmions play an essential role in spintronics applications, providing promising prospects for the development of future high-speed memory and logic devices. Recently the most widely investigated mechanism in this field is the Dzyaloshinsky-Moriya interaction, appearing due to the presence of inversion symmetry breaking at surfaces and interfaces and the strong spin-orbit coupling from heavy metal substrates. Using ab initio calculations and classical spin model simulations, we demonstrate how the presence of frustrated Heisenberg exchange interaction interplays with the Dzyaloshinsky-Moriya interaction, changing the interaction potential landscape for isolated skyrmions [1] and stabilizing localized configurations with different topological charges [2]. We also show an example of how interaction parameters resolved within atomic layers can explain a significant modulation of the magnetic period length in ultrathin films, recently investigated in three-atomic-layer-thick Fe films grown on Ir(111) surface using spin-polarized scanning tunneling microscopy experiments [3].
[1] L. Rózsa, A. Deák, E. Simon, R. Yanes, L. Udvardi, L. Szunyogh, and U. Nowak, Phys. Rev. Lett. 117, 157205 (2016)
[2] L. Rózsa, K. Palotás, A. Deák, E. Simon, R. Yanes, L. Udvardi, L. Szunyogh, and U. Nowak, Phys. Rev. B 95, 094423 (2017)
[3] A. Finco, L. Rózsa, P.-J. Hsu, A. Kubetzka, E. Vedmedenko, K. von Bergmann, and R. Wiesendanger, Phys. Rev. Lett. 119, 037202 (2017)
