CaltechAUTHORS
Published February 15, 2012 | Version Published
Journal Article Open

Single-valley quantum Hall ferromagnet in a dilute Mg_xZn_(1−x)O/ZnO strongly correlated two-dimensional electron system

Creators

  • 1. ROR icon University of Tokyo
  • 2. ROR icon Japan Science and Technology Agency
  • 3. ROR icon RIKEN Advanced Science Institute
  • 4. ROR icon Stanford University
  • 5. ROR icon Tohoku University

Abstract

We investigate the spin susceptibility (g^∗m^∗) of dilute two-dimensional (2D) electrons confined at the Mg_xZn_(1−x)O/ZnO heterointerface. Magnetotransport measurements show a four-fold enhancement of g^∗m^∗, dominated by the increase in the Landé g-factor. The g-factor enhancement leads to a ferromagnetic instability of the electron gas as evidenced by sharp resistance spikes. At high magnetic field, the large g^∗m^∗ leads to full spin polarization, where we found sudden increase in resistance around the filling factors of half-integer, accompanied by complete disappearance of fractional quantum Hall (QH) states. Along with its large effective mass and the high electron mobility, our result indicates that the ZnO 2D system is ideal for investigating the effect of electron correlations in the QH regime.

Additional Information

© 2012 American Physical Society. (Received 12 January 2012; published 3 February 2012) This work was partly supported by Grant-in-Aids for Scientific Research No. 22840004 (Y.K.) from MEXT, Japan, and by "Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST)" Program from the Japan Society for the Promotion of Science (JSPS) initiated by the Council for Science and Technology Policy (A.T.) as well as by Asahi Glass Foundation (Y.K. and M.K.). C.B., M.K., Y.H., and H.Y.H. acknowledge support by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under contract DE-AC02-76SF00515.

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Published - PhysRevB.85.075302.pdf

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Additional details

Identifiers

Eprint ID
102302
Resolver ID
CaltechAUTHORS:20200402-144734572

Funding

Ministry of Education, Culture, Sports, Science and Technology (MEXT)
22840004
Japan Society for the Promotion of Science (JSPS)
Council for Science and Technology Policy (CSTP)
Asahi Glass Foundation
Department of Energy (DOE)
DE-AC02-76SF00515

Dates

Created
2020-04-02
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Updated
2021-11-16
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