title: Nanoscale Probing of Local Electrical Characteristics on MBE-Grown Bi₂Te₃ Surfaces under Ambient Conditions.
abstract: The local electrical characteristics on the surface of MBE-grown Bi2Te3 are probed under ambient conditions by conductive atomic force microscopy. Nanoscale mapping reveals a 10-100× enhancement in current at step-edges compared to that on terraces. Analysis of the local current-voltage characteristics indicates that the transport mechanism is similar for step-edges and terraces. Comparison of the results with those for control samples shows that the current enhancement is not a measurement artifact but instead is due to local differences in electronic properties. The likelihood of various possible mechanisms is discussed. The absence of enhancement at the step-edges for graphite terraces is consistent with the intriguing possibility that spin-orbit coupling and topological effects play a significant role in the step-edge current enhancement in Bi2Te3.
authors.affiliation: †Department of Electrical and Computer Engineering, University of California Davis, Davis, California 95616, United States.
authors.forename: Rita J
authors.initials: RJ
authors.lastname: Macedo
authors.affiliation: ‡Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Harrison
authors.affiliation: †Department of Electrical and Computer Engineering, University of California Davis, Davis, California 95616, United States.
authors.forename: Tatiana S
authors.initials: TS
authors.lastname: Dorofeeva
authors.affiliation: ‡Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States.
authors.forename: James S
authors.initials: JS
authors.lastname: Harris
authors.affiliation: †Department of Electrical and Computer Engineering, University of California Davis, Davis, California 95616, United States.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kiehl
keywords: Bismuth telluride; atomic force microscopy; molecular beam epitaxy; topological insulators; van der Waals epitaxy