10.1184/R1/6506828.v1 Kendal W. Clark Kendal W. Clark X.-G. Zhang X.-G. Zhang Gong Gu Gong Gu Jewook Park Jewook Park Guowei He Guowei He Randall Feenstra Randall Feenstra An-Ping Li An-Ping Li Friedel Oscillation-Induced Energy Gap Manifested as Transport Asymmetry at Monolayer-Bilayer Graphene Boundaries Carnegie Mellon University 2014 Condensed Matter Physics Graphene Scanning Tunneling Microscopy 2014-02-01 00:00:00 Journal contribution https://kilthub.cmu.edu/articles/journal_contribution/Friedel_Oscillation-Induced_Energy_Gap_Manifested_as_Transport_Asymmetry_at_Monolayer-Bilayer_Graphene_Boundaries/6506828 <p>We show that Friedel charge oscillation near an interface opens a gap at the Fermi energy for electrons with wave vectors perpendicular to the interface. If the Friedel gaps on two sides of the interface are different, a nonequilibrium effect—shifting of these gaps under bias—leads to asymmetric transport upon reversing the bias polarity. The predicted transport asymmetry is revealed by scanning tunneling potentiometry at monolayer-bilayer interfaces in epitaxial graphene on SiC(0001). This intriguing interfacial transport behavior opens a new avenue toward novel quantum functions such as quantum switching.</p>