Abstract
We fabricate high-mobility -type few-layer field-effect transistors and surprisingly observe a series of quantum Hall (QH) states following an unconventional sequence predominated by odd-integer states under a moderate strength magnetic field. By tilting the magnetic field, we discover Landau level crossing effects at ultralow coincident angles, revealing that the Zeeman energy is about 3 times as large as the cyclotron energy near the valence band top at the valley. This result implies the significant roles played by the exchange interactions in -type few-layer , in which itinerant or QH ferromagnetism likely occurs. Evidently, the valley of few-layer offers a unique platform with unusually heavy hole carriers and a substantially enhanced factor for exploring strongly correlated phenomena.
- Received 3 November 2016
DOI:https://doi.org/10.1103/PhysRevLett.118.067702
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