Scanning tunneling microscopy of an interfacial two-dimensional electron gas in oxide heterostructures
Abstract
Using an advanced technique combining pulsed laser deposition growth of LaAl O3 , LaTi O3 , and SrTi O3 we effectively constructed half-integer unit cell number LaAl O3-SrTi O3 heterostructures where all interfaces are of LaO-Ti O2 type, and where a two-dimensional electron gas (2DEG) forms a symmetric n -type bilayer. Using ultrahigh-vacuum scanning tunneling microscopy we investigated the properties of the surface 2DEG in these heterostructures. Our results indicate that the surface 2DEG is strongly, within one unit cell, confined at the interface. Tunneling spectroscopy of the surface 2DEG reveals thickness-dependent band-gap changes attributed to the quantum size effect.
- Publication:
-
Physical Review B
- Pub Date:
- March 2016
- DOI:
- 10.1103/PhysRevB.93.115437
- Bibcode:
- 2016PhRvB..93k5437A