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All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
A New Model Employing Fermi-Level Integration Limits to Correct Systematic Errors in the Extraction of Semimetal
Y W Sun1,2, D Holec3, O Fenwick2
1School of Physics and Astronomy, University of Birmingham, BirminghamB15 2TT, United Kingdom.
Abstract:
We demonstrate that the accepted model for transport in semimetals gives incorrect results and introduce a corrected scheme that reproduces experimental data. Carrier densities in semimetals have been systematically overestimated by factors of 2-5 throughout the literature, leading to underestimated mobilities by the same factor. This resolves the long-standing puzzle of why nominally identical graphene samples show order-of-magnitude mobility variations. By integrating the density of states from the Fermi level rather than from band edges, we reproduce the full evolution of the Hall coefficient and longitudinal resistance across five independent graphene data sets with zero fitting parameters. A double-normalized polar representation reveals a decisive signature: a smooth arc that experimental data match, while no realistic density of states or mobility rescues the band-edge model. Our Fermi model provides a parameter-free, temperature-robust description with immediate implications for reevaluating mobility benchmarks across the 2D materials literature.
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