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Title: Berry phase mechanism of the anomalous Hall effect in a disordered two-dimensional magnetic semiconductor structure.

In this study, the anomalous Hall effect (AHE) arises from the interplay of spin-orbit interactions and ferromagnetic order and is a potentially useful probe of electron spin polarization, especially in nanoscale systems where direct measurement is not feasible. While AHE is rather well-understood in metallic ferromagnets, much less is known about the relevance of different physical mechanisms governing AHE in insulators. As ferromagnetic insulators, but not metals, lend themselves to gatecontrol of electron spin polarization, understanding AHE in the insulating state is valuable from the point of view of spintronic applications. Among the mechanisms proposed in the literature for AHE in insulators, the one related to a geometric (Berry) phase effect has been elusive in past studies. The recent discovery of quantized AHE in magnetically doped topological insulators - essentially a Berry phase effect - provides strong additional motivation to undertake more careful search for geometric phase effects in AHE in the magnetic semiconductors. Here we report our experiments on the temperature and magnetic field dependences of AHE in insulating, strongly-disordered two-dimensional Mn delta-doped semiconductor heterostructures in the hopping regime. In particular, it is shown that at sufficiently low temperatures, the mechanism of AHE related to the Berry phase ismore » favoured.« less
 [1] ;  [2] ;  [3] ;  [1] ;  [4] ;  [5] ;  [3] ;  [6]
  1. National Research Center Kurchatov Institute, Moscow (Russia); Russian Acad. Sci., Moscow (Russia)
  2. National Research Center Kurchatov Institute, Moscow (Russia); M. V. Lomonosov Moscow State Univ., Moscow (Russia)
  3. Russian Acad. Sci., Moscow (Russia)
  4. Russian Acad. Sci., St. Petersburg (Russia); Peter the Great St. Petersburg Polytechnic Univ., St. Petersburg (Russia)
  5. Russian Acad. Sci., St. Petersburg (Russia)
  6. Argonne National Lab. (ANL), Argonne, IL (United States); Tata Institute of Fundamental Research, Mumbai (India)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 5; Journal Issue: 16; Journal ID: ISSN 2045-2322
Nature Publishing Group
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; magnetic properties and materials; spintronics; two-dimensional materials