物理学院 School of Physics, Nanjing University

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Predicted Quantum Topological Hall Effect in K0.5RhO2

2016年09月12日


报告人:现代工程与应用科学学院 周健副教授
报告时间:9月13日
 中午1200
报告地点:唐楼 B501
题目: Predicted Quantum Topological Hall Effect in  K0.5RhO2

 
摘要: Quantum anomalous Hall (QAH) phase is a two-dimensional bulk ferromagnetic insulator with a nonzero Chern number in presence of spin-orbit coupling (SOC) but in the absence of applied magnetic fields. Associated metallic chiral edge states host dissipationless current transport in electronic devices. This intriguing QAH phase has recently been observed in magnetic impurity-doped topological insulators, albeit, at extremely low temperatures. Based on first-principles density functional calculations, here we predict  that layered rhodium oxide 
K0.5RhO2 in noncoplanar chiral antiferromagnetic state is an unconventional three-dimensional QAH insulator with a large band gap and a Neel temperature of a few tens Kelvins.
Furthermore, this unconventional QAH phase is revealed to be the exotic quantum topological Hall effect caused by nonzero scalar spin chirality due to the topological spin structure in the 
system and without the need of net magnetization and SOC.

参考文献:
PRL 116,256601(2016)

报告人简介:
周健:  南京大学现代工程与应用科学学院副教授,2002 年南京大学物理系学士;2007年南京大学物理系博士;2007-2009年南京大学材料科学与工程系博士后;2009 年9 月起在南京大学现代工程与应用科学学院,从事教学和科研工作,主要研究方向为二维和层状材料电子结构和光学性质的第一性原理计算。

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