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Title: Chiral transport along magnetic domain walls in the quantum anomalous Hall effect

The recent prediction, and subsequent discovery, of the quantum anomalous Hall (QAH) effect in thin films of the three-dimensional ferromagnetic topological insulator (MTI) (Cr$$_y$$Bi$$_x$$Sb$$_{1-x-y}$$)$$_2$$Te$$_3$$ has opened new possibilities for chiral-edge-state-based devices in zero external magnetic field. Like the $$\nu=1$$ quantum Hall system, the QAH system is predicted to have a single chiral edge mode circulating along the boundary of the film. Backscattering of the chiral edge mode should be suppressed, as recently verified by the observation of well-quantized Hall resistivities $$\rho_{yx} = \pm h/e^2$$, along with longitudinal resistivities as low as a few ohms. Dissipationless 1D conduction is also expected along magnetic domain walls. Here, we intentionally create a magnetic domain wall in a MTI and study electrical transport along the domain wall. We present the first observation of chiral transport along domain walls, in agreement with theoretical predictions. We present further evidence that two modes equilibrate and co-propagate along the length of the domain wall.
Authors:
 [1] ;  [1] ; ORCiD logo [2] ;  [3] ;  [3] ;  [1]
  1. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)
  2. Univ. of California, Los Angeles, CA (United States); ShanghaiTech Univ., Shanghai (China)
  3. Univ. of California, Los Angeles, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-76SF00515; GBMF3429; W911NF-16-1-0472; 17YF1429200; W911NF-15-1-0561:P00001
Type:
Accepted Manuscript
Journal Name:
npj Quantum Materials
Additional Journal Information:
Journal Volume: 2; Journal Issue: 1; Journal ID: ISSN 2397-4648
Publisher:
Nature Publishing Group
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Gordon and Betty Moore Foundation; National Science Foundation (NSF); US Army Research Office (ARO)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Quantum Hall; Topological insulators
OSTI Identifier:
1408888