Reversible metal-insulator transition of Ar-irradiated LaAlO3/SrTiO3 interfaces
Journal article, 2015

The conducting state of a quasi-two-dimensional electron gas (q2DEG), formed at the heterointerface between the two wide-bandgap insulators LaAlO3 (LAO) and SrTiO3, can be made completely insulating by low-energy, 150-eV, Ar+ irradiation. The metallic behavior of the interface can be recovered by high-temperature oxygen annealing. The electrical transport properties of the recovered q2DEG are exactly the same as before the irradiation. Microstructural investigations confirm that the transition is not due to physical etching or crystal lattice distortion of the LAO film below its critical thickness. They also reveal a correlation between electrical state, LAO film surface amorphization, and argon ion implantation. The experimental results are in agreement with density functional theory calculations of Ar implantation and migration in the LAO film. This suggests that the metal-insulator transition may be caused by charge trapping in the defect amorphous layer created during the ion irradiation.

Author

Pier Paolo Aurino

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Alexei Kalaboukhov

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Nikolina Tuzla

Chalmers, Applied Physics, Eva Olsson Group

Eva Olsson

Chalmers, Applied Physics, Eva Olsson Group

A. Klein

Technische Universität Darmstadt

Paul Erhart

Chalmers, Applied Physics, Materials and Surface Theory

Y. A. Boikov

Russian Academy of Sciences

I.T. Serenkov

Russian Academy of Sciences

V.I. Sakharov

Russian Academy of Sciences

Tord Claeson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Dag Winkler

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 92 15 155130

Subject Categories

Nano Technology

DOI

10.1103/PhysRevB.92.155130

More information

Latest update

7/4/2018 1