Magnetoresistance and quantum oscillations of an electrostatically tuned semimetal-to-metal transition in ultrathin
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Princeton Univ., NJ (United States)
- National Institute for Materials Science (NIMS), Tsukuba (Japan). Advanced Materials Lab.
In this work, we report on electronic transport measurements of electrostatically gated nanodevices of the semimetal WTe2. High mobility metallic behavior is achieved in the 2D limit by encapsulating thin flakes in an inert atmosphere. At low temperatures, we find that a large magnetoresistance can be turned on and off by electrostatically doping the system between a semimetallic state and an electron-only metallic state, respectively. We confirm the nature of the two regimes by analyzing the magnetoresistance and Hall effect with a two-carrier model, as well as by analysis of Shubnikov-de Haas oscillations, both of which indicate depletion of hole carriers via the electrostatic gate. This confirms that semiclassical transport of two oppositely charged carriers accurately describes the exceptional magnetoresistance observed in this material. Finally, we also find that the magnetoresistance power law is subquadratic and density independent, suggesting new physics specifically in the semimetallic regime.
- Research Organization:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; National Science Foundation (NSF); US Air Force Office of Scientific Research (AFOSR); Gordon and Betty Moore Foundation; USDOE
- Grant/Contract Number:
- SC0001088; SC0006418; ECS-0335765; DMR-0819762; DMR-1005438; FA9550-16-1-0382; GBMF4541
- OSTI ID:
- 1535836
- Alternate ID(s):
- OSTI ID: 1341916
- Journal Information:
- Physical Review. B, Vol. 95, Issue 4; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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