Stable humplike Hall effect and noncoplanar spin textures in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>SrRuO</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msub></mml:math> ultrathin films
Byungmin Sohn, Bongju Kim, Se Young Park, Hwan Young Choi, Jae Young Moon, Taeyang Choi, Young Jai Choi, Hua Zhou, Jun Woo Choi, Alessandro Bombardi, Dan. G. Porter, Seo Hyoung Chang, Jung Hoon Han, Changyoung Kim
Abstract
We observed a humplike feature in Hall effects of SrRuO 3 ultrathin films, and systematically investigated it by controlling thicknesses, temperatures and magnetic fields. The humplike feature is extremely stable, even surviving as a magnetic field is tilted by as much as 85 . Based on the atomic-level structural analysis of a SrRuO 3 ultrathin film with a theoretical calculation, we reveal that atomic rumplings at the thin-film surface enhance Dzyaloshinskii-Moriya interaction, which can generate stable chiral spin textures and a humplike Hall effect. Moreover, temperature dependent resonant x-ray measurements at the Ru L edge under a magnetic field showed that the intensity modulation of unexpected peaks was correlated with the hump region in the Hall effect. We verify that the two-dimensional property of ultrathin films generates stable noncoplanar spin textures having a magnetic order in a ferromagnetic oxide material.