Berry phase manipulation in ultrathin <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>SrRuO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math> films
Liang Wu, Fangdi Wen, Yixing Fu, Justin H. Wilson, Xiaoran Liu, Yujun Zhang, Denis M. Vasiukov, M. Kareev, J. H. Pixley, J. Chakhalian
Abstract
Ultrathin SrRuO${}_{3}$ has a nontrivial Hall response that looks strikingly like a skyrmion-induced topological Hall effect. Here, the authors demonstrate how the Berry phase alone, without skyrmions, provides a comprehensive explanation for such a Hall response. The Berry phase contribution to the Hall effect can be altered, enhanced, and even change sign in response to the number of layers, temperature, and, importantly, disorder. By comparing the effects of disorder, theoretically, on a skyrmion model and on a spin-orbit coupled model, only the latter can capture the experimentally observed enhancement of the anomalous Hall effect in the more disordered samples.