Open AccessKerr effect anomaly in magnetic topological insulator superlattices
Author(s) -
Jieyi Liu,
Angadjit Singh,
Balati Kuerbanjiang,
C. H. W. Barnes,
T. Hesjedal
Publication year - 2020
Publication title -
nanotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.926
H-Index - 203
eISSN - 1361-6528
pISSN - 0957-4484
DOI - 10.1088/1361-6528/aba210
Subject(s) - superlattice , condensed matter physics , topological insulator , skyrmion , kerr effect , ferromagnetism , magnetization , materials science , magneto optic kerr effect , hall effect , topology (electrical circuits) , magnetic field , physics , quantum mechanics , mathematics , nonlinear system , combinatorics
We report the magneto-optical Kerr effect (MOKE) study of magnetic topological insulator superlattice films with alternating transition-metal and rare-earth doping. We observe an unexpected hump in the MOKE hysteresis loops upon magnetization reversal at low temperatures, reminiscent of the topological Hall effect (THE) reported in transport measurements. The THE is commonly associated with the existence of magnetic skyrmions, i.e. chiral spin textures originating from topological defects in real space. Here, the observation of the effect is tied to ferromagnetic ordering in the rare-earth-doped layers of the superlattice. Our study may provide a new approach for the non-invasive optical investigation of skyrmions in magnetic films, complementary to electrical transport measurements, where the topological Hall signal is often the only hint of non-trivial magnetization patterns.