Polshyn, HryhoriyISTA ; Zhang, Yuxuan; Yankowitz, Matthew; Chen, Shaowen; Taniguchi, Takashi; Watanabe, Kenji; Graf, David E.; Dean, Cory R.; Young, Andrea
Bulletin of the American Physical Society
Twisted bilayer graphene (tBLG) near the flat band condition is a versatile new platform for the study of correlated physics in 2D. Resistive states have been observed at several commensurate fillings of the flat miniband, along with superconducting states near half filling. To better understand the electronic structure of this system, we study electronic transport of graphite gated superconducting tBLG devices in the normal regime. At high magnetic fields, we observe full lifting of the spin and valley degeneracy. The transitions in the splitting of this four-fold degeneracy as a function of carrier density indicate Landau level (LL) crossings, which tilted field measurements show occur between LLs with different valley polarization. Similar LL structure measured in two devices, one with twist angle θ=1.08° at ambient pressure and one at θ=1.27° and 1.33GPa, suggests that the dimensionless combination of twist angle and interlayer coupling controls the relevant details of the band structure. In addition, we find that the temperature dependence of the resistance at B=0 shows linear growth at several hundred Ohm/K in a broad range of temperatures. We discuss the implications for modeling the scattering processes in this system.
APS March Meeting 2019
APS: American Physical Society
Boston, MA, United States
2019-03-04 – 2019-03-08
Polshyn H, Zhang Y, Yankowitz M, et al. Normal state transport in superconducting twisted bilayer graphene. In: APS March Meeting 2019. Vol 64. American Physical Society; 2019.
Polshyn, H., Zhang, Y., Yankowitz, M., Chen, S., Taniguchi, T., Watanabe, K., … Young, A. (2019). Normal state transport in superconducting twisted bilayer graphene. In APS March Meeting 2019 (Vol. 64). Boston, MA, United States: American Physical Society.
Polshyn, Hryhoriy, Yuxuan Zhang, Matthew Yankowitz, Shaowen Chen, Takashi Taniguchi, Kenji Watanabe, David E. Graf, Cory R. Dean, and Andrea Young. “Normal State Transport in Superconducting Twisted Bilayer Graphene.” In APS March Meeting 2019, Vol. 64. American Physical Society, 2019.
H. Polshyn et al., “Normal state transport in superconducting twisted bilayer graphene,” in APS March Meeting 2019, Boston, MA, United States, 2019, vol. 64, no. 2.
Polshyn H, Zhang Y, Yankowitz M, Chen S, Taniguchi T, Watanabe K, Graf DE, Dean CR, Young A. 2019. Normal state transport in superconducting twisted bilayer graphene. APS March Meeting 2019. APS: American Physical Society, Bulletin of the American Physical Society, vol. 64, V14.00008.
Polshyn, Hryhoriy, et al. “Normal State Transport in Superconducting Twisted Bilayer Graphene.” APS March Meeting 2019, vol. 64, no. 2, V14.00008, American Physical Society, 2019.
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