Dielectric collapse at the LaAlO3/SrTiO3 (001) heterointerface under applied electric field.
Sci Rep
; 7(1): 9516, 2017 08 25.
Article
en En
| MEDLINE
| ID: mdl-28842643
ABSTRACT
The fascinating interfacial transport properties at the LaAlO3/SrTiO3 heterointerface have led to intense investigations of this oxide system. Exploiting the large dielectric constant of SrTiO3 at low temperatures, tunability in the interfacial conductivity over a wide range has been demonstrated using a back-gate device geometry. In order to understand the effect of back-gating, it is crucial to assess the interface band structure and its evolution with external bias. In this study, we report measurements of the gate-bias dependent interface band alignment, especially the confining potential profile, at the conducting LaAlO3/SrTiO3 (001) heterointerface using soft and hard x-ray photoemission spectroscopy in conjunction with detailed model simulations. Depth-profiling analysis incorporating the electric field dependent dielectric constant in SrTiO3 reveals that a significant potential drop on the SrTiO3 side of the interface occurs within ~2 nm of the interface under negative gate-bias. These results demonstrate gate control of the collapse of the dielectric permittivity at the interface, and explain the dramatic loss of electron mobility with back-gate depletion.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Sci Rep
Año:
2017
Tipo del documento:
Article
País de afiliación:
Estados Unidos