Quantum Hall ferromagnetic transition in a Ge 2D hole system

Technical Report · Thu Dec 01 04:00:00 EST 2016

DOI:https://doi.org/10.2172/1505345· OSTI ID:1505345

Lu, Tzu-Ming ^[1]; Tracy, Lisa A. ^[1]; Laroche, D. ^[1]; Huang, S. H. ^[2]; Chuang, Y. ^[2]; Su, Y. H. ^[2]; Li, J. Y. ^[2]; Liu, C. W. ^[2]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2. National Taiwan Univ., Taipei (Taiwan)

When two Landau levels are brought into energy degeneracy, interesting phases and phase transitions can occur. For single-layer 2D electrons, a quantum Hall ferromagnetic transition (QHFT) occurs when Landau levels with opposite spins are made degenerate by an in-plane magnetic field, which enhances the Zeeman splitting but keeps the cyclotron energy constant. At the QHFT, the 2D electron system breaks up into magnetic domains with opposite spins, and a resistance spike is observed as electrons move through the domain wall loops. An alternative way to enhance the ratio of Zeeman splitting to the cyclotron energy, which is proportional to m*g*, is to reduce the carrier density (p). Here we report the observation of a QHFT at ν = 2 in a Ge 2D hole system through modulating p without any in-plane magnetic field. We also report the effects of an in-plane magnetic field to this QHFT.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF); Ministry of Science and Technology (MOST), Taipei (Taiwan)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1505345
• Report Number(s): SAND--2016-12433R; 649783
• Country of Publication: United States
• Language: English

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