TY - JOUR
KW - Titanium compounds
KW - Electric fields
KW - Lanthanum compounds
KW - Strontium titanates
KW - Heterojunctions
KW - Aluminum compounds
KW - Vanadium compounds
KW - Electron gas
KW - Phase interfaces
KW - Built-in potential
KW - Capacitance measurement
KW - Built-in electric fields
KW - Device architectures
KW - Electrostatic stability
KW - Induced dipole moments
KW - Induced polarization
KW - Metallic electrodes
KW - SrTiO3 substrates
AU - G Singh-Bhalla
AU - C Bell
AU - J Ravichandran
AU - W Siemons
AU - Y Hikita
AU - S Salahuddin
AU - A.F Hebard
AU - H.Y Hwang
AU - Ramamoorthy Ramesh
AB - Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely charged atomic planes gives rise to a built-in potential that diverges with thickness. Here we present evidence of such a built-in potential across polar LaAlO 3 thin films grown on SrTiO 3 substrates, a system well known for the electron gas that forms at the interface. By carrying out tunnelling measurements between the electron gas and metallic electrodes on LaAlO 3 we measure a built-in electric field across LaAlO 3 of 80.1 meV Å -1 . In addition, capacitance measurements reveal the presence of an induced dipole moment across the heterostructure. We foresee use of the ionic built-in potential as an additional tuning parameter in both existing and future device architectures, especially as atomic control of oxide interfaces gains widespread momentum. © 2011 Macmillan Publishers Limited. All rights reserved.
BT - Nature Physics
DO - 10.1038/nphys1814
LA - eng
M1 - 1
N1 - cited By 147
N2 - Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely charged atomic planes gives rise to a built-in potential that diverges with thickness. Here we present evidence of such a built-in potential across polar LaAlO 3 thin films grown on SrTiO 3 substrates, a system well known for the electron gas that forms at the interface. By carrying out tunnelling measurements between the electron gas and metallic electrodes on LaAlO 3 we measure a built-in electric field across LaAlO 3 of 80.1 meV Å -1 . In addition, capacitance measurements reveal the presence of an induced dipole moment across the heterostructure. We foresee use of the ionic built-in potential as an additional tuning parameter in both existing and future device architectures, especially as atomic control of oxide interfaces gains widespread momentum. © 2011 Macmillan Publishers Limited. All rights reserved.
PB - Nature Publishing Group
PY - 2011
SP - 80
EP - 86
T2 - Nature Physics
TI - Built-in and induced polarization across LaAlO 3 /SrTiO 3 heterojunctions
VL - 7
SN - 17452473
ER -