Electronic Compressibility of Magic-Angle Graphene Superlattices
Name
PhysRevLett.123.046601.pdf
Description
Published version
Size
825.97 KB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
Tomarken, Spencer Louis
Cao, Yuan
Demir, Ahmet
Jarillo-Herrero, Pablo
Ashoori, Raymond
Date Issued
July 2019
Journal
Physical Review Letters
Publisher
American Physical Society (APS)
Citation
Tomarken, S. L. et al. “Electronic Compressibility of Magic-Angle Graphene Superlattices.” Physical Review Letters, 123, 4 (July 2019): 046601 © 2019 The Author(s)
Version
Final published version
Abstract
We report the first electronic compressibility measurements of magic-angle twisted bilayer graphene. The evolution of the compressibility with carrier density offers insights into the interaction-driven ground state that have not been accessible in prior transport and tunneling studies. From capacitance measurements, we determine the chemical potential as a function of carrier density and find the widths of the energy gaps at fractional filling of the moiré lattice. In the electron-doped regime, we observe unexpectedly large gaps at quarter- and half-filling and strong electron-hole asymmetry. Moreover, we measure a ∼35 meV minibandwidth that is much wider than most theoretical estimates. Finally, we explore the field dependence up to the quantum Hall regime and observe significant differences from transport measurements.
MIT Department
Massachusetts Institute of Technology. Department of Physics
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DOI of Published Version
https://doi.org/10.1103/PHYSREVLETT.123.046601
