Polarization Control of Electron Tunneling into Ferroelectric Surfaces
Peter Maksymovych,1,*
Stephen Jesse,1
Pu Yu,2
Ramamoorthy Ramesh,2
Arthur P. Baddorf,1
Sergei V. Kalinin1
We demonstrate a highly reproducible control of local electron
transport through a ferroelectric oxide via its spontaneous
polarization. Electrons are injected from the tip of an atomic
force microscope into a thin film of lead-zirconate titanate,
Pb(Zr
0.2Ti
0.8)O
3, in the regime of electron tunneling assisted
by a high electric field (Fowler-Nordheim tunneling). The tunneling
current exhibits a pronounced hysteresis with abrupt switching
events that coincide, within experimental resolution, with the
local switching of ferroelectric polarization. The large spontaneous
polarization of the PZT film results in up to 500-fold amplification
of the tunneling current upon ferroelectric switching. The magnitude
of the effect is subject to electrostatic control via ferroelectric
switching, suggesting possible applications in ultrahigh-density
data storage and spintronics.
2 Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, CA 94720, USA.
* To whom correspondence should be addressed. E-mail: maksymovychp{at}ornl.gov
