Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 20: Correlated Electrons - Poster Session

TT 20.46: Poster

Mittwoch, 28. März 2007, 14:00–17:45, Poster A

Electric transport properties of LaAlO₃/SrTiO₃ interfaces studied by scanning electron microscopy — •Christian Gürlich¹, Matthias Ruoff¹, Stefan Thiel², Christof Schneider², German Hammerl², Christoph Richter², Jochen Mannhart², Reinhold Kleiner¹, and Dieter Koelle¹ — ¹Physikalisches Institut, Experimentalphysik II, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany — ²Center for Electronic Correlations and Mangnetism, Institut of Physics, Augsburg University, D-86135 Augsburg, Germany

It was shown recently that conducting electron gases are formed at interfaces in heterostructures consisting of insulating oxides such as SrTiO₃/LaTiO₃ (STO/LTO) or LaAlO₃/SrTiO₃ (LAO/STO) [1]. These conducting electron gases might be confined to sheets that are only very few nanometers thick. Lateral confinement into a bridge-like structure has been realized for STO/LAO interfaces, using lithographic patterning by modulating the thickness of the LAO layers with unit cell resolution [2]. Here, we present a scanning electron microscopy study of the electric transport properties of such structures. Irradiation with a focused electron beam induces pronounced changes of the sample resistance, with a typical reduction by more than a factor of two at 300 K. After switching off the electron beam, the resistance returns to the initial state with relaxation times above several hundred seconds.

[1] H. Y. Hwang, Science vol. 313, 1895 (2006) and references therein.

[2] C. W. Schneider et al., Appl. Phys. Lett. vol. 89, 122101 (2006).