Berlin 2012 – scientific programme
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MA: Fachverband Magnetismus
MA 13: Magnetic Materials
MA 13.14: Talk
Monday, March 26, 2012, 18:30–18:45, H 0112
Mechanisms of enhanced orbital dia- and paramagnetism: Application to the Rashba semiconductor BiTeI — •Giulio Albert Heinrich Schober1,2,3, Hiroshi Murakawa4, Mohammad Saeed Bahramy4, Ryotaro Arita1,4, Yoshio Kaneko5, Yoshinori Tokura1,3,4,5, and Naoto Nagaosa1,3,4 — 1Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan — 2Institute for Theoretical Physics, University of Heidelberg, D-69120 Heidelberg, Germany — 3Cross-Correlated Materials Research Group (CMRG), ASI, RIKEN, Wako 351-0198, Japan — 4Correlated Electron Research Group (CERG), ASI, RIKEN, Wako 351-0198, Japan — 5Multiferroics Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), c/o Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
We study the magnetic susceptibility of a layered semiconductor BiTeI with giant Rashba spin splitting both theoretically and experimentally to explore its orbital magnetism. Apart from the core contributions, a large temperature-dependent diamagnetic susceptibility is observed when the Fermi energy EF is near the crossing point of the conduction bands, while the susceptibility turns to be paramagnetic when EF is away from it. These features are consistent with first-principles calculations, which also predict an enhanced orbital magnetic susceptibility with both positive and negative signs as a function of EF due to band (anti)crossings. Based on these observations, we propose two mechanisms for an enhanced paramagnetic orbital susceptibility.