title: Conductivity map from scanning tunneling potentiometry.
abstract: We present a novel method for extracting two-dimensional (2D) conductivity profiles from large electrochemical potential datasets acquired by scanning tunneling potentiometry of a 2D conductor. The method consists of a data preprocessing procedure to reduce/eliminate noise and a numerical conductivity reconstruction. The preprocessing procedure employs an inverse consistent image registration method to align the forward and backward scans of the same line for each image line followed by a total variation (TV) based image restoration method to obtain a (nearly) noise-free potential from the aligned scans. The preprocessed potential is then used for numerical conductivity reconstruction, based on a TV model solved by accelerated alternating direction method of multiplier. The method is demonstrated on a measurement of the grain boundary of a monolayer graphene, yielding a nearly 10:1 ratio for the grain boundary resistivity over bulk resistivity.
authors: Department of Mathematics, University of Florida, Gainesville, Florida 32611, USA.
authors: Hao
authors: H
authors: Zhang
authors: Department of Mathematics, University of Florida, Gainesville, Florida 32611, USA.
authors: Xianqi
authors: X
authors: Li
authors: Department of Mathematics, University of Florida, Gainesville, Florida 32611, USA.
authors: Yunmei
authors: Y
authors: Chen
authors: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6493, USA.
authors: Corentin
authors: C
authors: Durand
authors: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6493, USA.
authors: An-Ping
authors: AP
authors: Li
authors: Department of Physics and the Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA.
authors: X-G
authors: XG
authors: Zhang