Chiral transport along magnetic domain walls in the quantum anomalous Hall effect. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Rosen, Ilan; Fox, Eli; Kou, Xufeng; Pan, Lei; Wang, Kang; Goldhaber-Gordon, David
• Is Part Of: Npj quantum materials. Volume 2:Issue 1(2017)
• Page Start: 1
• Page End: 6
• Publication Date: 2017-12
• Subjects: Superconductors -- Periodicals; Quantum theory -- Periodicals; 530.12
• DOI: 10.1038/s41535-017-0073-0
• Languages: English
• ISSNs: 2397-4648

Abstract

Abstract The quantum anomalous Hall effect in thin film magnetic topological insulators (MTIs) is characterized by chiral, one-dimensional conduction along the film edges when the sample is uniformly magnetized. This has been experimentally confirmed by measurements of quantized Hall resistance and near-vanishing longitudinal resistivity in magnetically doped (Bi, Sb)2 Te3 . Similar chiral conduction is expected along magnetic domain walls, but clear detection of these modes in MTIs has proven challenging. Here, we intentionally create a magnetic domain wall in an MTI, and study electrical transport along the domain wall. In agreement with theoretical predictions, we observe chiral transport along a domain wall. We present further evidence that two modes equilibrate while co-propagating along the length of the domain wall. Topological materials: magnetic domains have the edge Chiral transport is observed along the domain walls in a magnetic topological insulator. The anomalous Hall effect was discovered in the 19th century, but it took over a hundred years to realize its quantized version. Observed in magnetic topological insulators, the quantum anomalous Hall effect is an example of a topological state of matter. As these systems are topologically non-trivial, chiral channels emerge at the edges of the material when interfaced with a topologically trivial phase, such as vacuum. An international team of researchers led by David Goldhaber-Gordon from Stanford University and the SLAC National Accelerator Laboratory now show that one-dimensional chiral transport also occurs along the domain walls in magnetic topological insulators. As these one-dimensional channels should be dissipationless, they could provide a route to developing low-power electronic devices.