@article{53b2a24f0aee4ac2bbccccc380a3e45a,
title = "Tunneling Hot Spots in Ferroelectric SrTiO3",
abstract = "Strontium titanate (SrTiO3) is the {"}silicon{"} in the emerging field of oxide electronics. While bulk properties of this material have been studied for decades, new unexpected phenomena have recently been discovered at the nanoscale, when SrTiO3 forms an ultrathin film or an atomically sharp interface with other materials. One of the striking discoveries is room-temperature ferroelectricity in strain-free ultrathin films of SrTiO3 driven by the TiSr antisite defects, which generate a local dipole moment polarizing the surrounding nanoregion. Here, we demonstrate that these polar defects are not only responsible for ferroelectricity, but also propel the appearance of highly conductive channels, {"}hot spots{"}, in the ultrathin SrTiO3 films. Using a combination of scanning probe microscopy experimental studies and theoretical modeling, we show that the hot spots emerge due to resonant tunneling through localized electronic states created by the polar defects and that the tunneling conductance of the hot spots is controlled by ferroelectric polarization. Our finding of the polarization-controlled defect-assisted tunneling reveals a new mechanism of resistive switching in oxide heterostructures and may have technological implications for ferroelectric tunnel junctions. It is also shown that the conductivity of the hot spots can be modulated by mechanical stress, opening a possibility for development of conceptually new electronic devices with mechanically tunable resistive states.",
author = "Haidong Lu and Daesu Lee and Konstantin Klyukin and Lingling Tao and Bo Wang and Hyungwoo Lee and Jungwoo Lee and Paudel, {Tula R.} and Chen, {Long Qing} and Tsymbal, {Evgeny Y.} and Vitaly Alexandrov and Eom, {Chang Beom} and Alexei Gruverman",
note = "Funding Information: This work was supported by the National Science Foundation (NSF) through Materials Research Science and Engineering Center (MRSEC) under Grant DMR-1420645. K.K., T.R.A., E.T., and V.A. acknowledge the Holland Computing Center at the University of Nebraska-Lincoln for providing computational resources. Work at the University of Wisconsin was supported by funding from the DOE Office of Basic Energy Sciences under award number DE-FG02-06ER46327. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. B.W. was funded by the Penn State MRSEC, Center for Nanoscale Science, under the award NSF DMR-1420620. L.Q.C. acknowledges NSF DMREF support under Grant DMR1629270. Funding Information: This work was supported by the National Science Foundation (NSF) through Materials Research Science and Engineering Center (MRSEC) under Grant DMR-1420645. K.K., T.R.A., E.T., and V.A. acknowledge the Holland Computing Center at the University of Nebraska-Lincoln for providing computational resources. Work at the University of Wisconsin was supported by funding from the DOE Office of Basic Energy Sciences under award number DE-FG02-06ER46327. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. B.W. was funded by the Penn State MRSEC, Center for Nanoscale Science under the award NSF DMR-1420620. L.Q.C. acknowledges NSF DMREF support under Grant DMR1629270. Publisher Copyright: {\textcopyright} 2017 American Chemical Society.",
year = "2018",
month = jan,
day = "10",
doi = "10.1021/acs.nanolett.7b04444",
language = "English (US)",
volume = "18",
pages = "491--497",
journal = "Nano Letters",
issn = "1530-6984",
publisher = "American Chemical Society",
number = "1",
}