Keynote11
Quantum anomalous Hall effect in topological insulators
Yayu Wang
Department of Physics, Tsinghua University, Beijing 100084, China
Abstract:
The anomalous Hall effect was discovered more than 130 years ago in ferromagnet,
where a Hall resistance exists even in the absence of external magnetic field. The
quantized version of the anomalous Hall effect has attracted much interest since the
discovery of quantum Hall effect in the 1980s. A few years ago, it was proposed that
quantum anomalous Hall effect may occur in magnetic topological insulators, but the
experimental realization has been elusive. In this talk we will first introduce the basic
ideas about the quantum Hall effect and topological insulators. We will then report
transport studies of magnetically doped topological insulator thin films grown by
molecular beam epitaxy. We have achieved systematic tuning of the electronic band
structure, magnetic ordering, and bulk band topology, which eventually led to the
experimental realization of the quantum anomalous Hall effect, i.e., the quantum
Hall effect in zero magnetic field.
Reference:
“Experimental observation of the quantum anomalous Hall effect in a magnetic
topological insulator”, Science 340, 167 (2013).