Overweg, Hiske Eggimann, Hannah Chen, Xi Slizovskiy, Sergey Eich, Marius Pisoni, Riccardo Lee, Yongjin Rickhaus, Peter Watanabe, Kenji Taniguchi, Takashi Fal’ko, Vladimir Ihn, Thomas Ensslin, Klaus Electrostatically Induced Quantum Point Contacts in Bilayer Graphene We report the fabrication of electrostatically defined nanostructures in encapsulated bilayer graphene, with leakage resistances below depletion gates as high as <i>R</i> ∼ 10 GΩ. This exceeds previously reported values of <i>R</i> = 10–100 kΩ.− We attribute this improvement to the use of a graphite back gate. We realize two split gate devices which define an electronic channel on the scale of the Fermi-wavelength. A channel gate covering the gap between the split gates varies the charge carrier density in the channel. We observe device-dependent conductance quantization of Δ<i>G</i> = 2<i>e</i><sup>2</sup>/<i>h</i> and Δ<i>G</i> = 4<i>e</i><sup>2</sup>/<i>h</i>. In quantizing magnetic fields normal to the sample plane, we recover the four-fold Landau level degeneracy of bilayer graphene. Unexpected mode crossings appear at the crossover between zero magnetic field and the quantum Hall regime. Δ G;Ω.;charge carrier density;device-dependent conductance quantization;Unexpected mode crossings;split gate devices;encapsulated bilayer graphene;Electrostatically Induced Quantum Point Contacts;quantum Hall regime;Landau level degeneracy 2017-12-29
    https://acs.figshare.com/articles/journal_contribution/Electrostatically_Induced_Quantum_Point_Contacts_in_Bilayer_Graphene/5743599
10.1021/acs.nanolett.7b04666.s001