Special Condensed Matter Physics Seminar: When two insulators become electronics – A peek into the field of oxide nanoelectronics

Abstract:

The conductance confined at the interface of complex oxide heterostructures provides new opportunities to explore nanoelectronic as well as nanoionic devices [1]. When two oxides intimately contact each other, charge redistribution or mass transfer of ions may occur. Herein we show interfacial redox reaction induced metallic conductivity along the interface of SrTiO3-based heterostructures with various oxide overlayers of amorphous LaAlO3, SrTiO3 (STO) and yttria-stabilized zirconia (YSZ) films [2]. Recently, we create a new type of 2DEG at the heterointerface between SrTiO3 and a spinel γ-Al2O3 epitaxial film with compatible oxygen ions sublattices [3]. Electron mobilities more than one order of magnitude higher than those of hitherto investigated perovskite-type interfaces are obtained. Particularly, electron Hall mobilities as large as 1.4×105 cm2V-1s-1 and ns as high as 3.7×1014 cm-2 at 2 K is obtained. These findings can pave the way for studies of mesoscopic physics with complex oxides and design of high-mobility all-oxide electronic devices.

Reference:

1. J. Mannhart & D. G. Schlom, Science 327, 1607-1611 (2010).

2. Y. Z. Chen et al. Metallic and insulating interfaces of amorphous SrTiO3-based oxide heterostructures. Nano. Lett. 11, 3774-3778 (2011).

3. Y. Z. Chen et al. Nat. Commun. 4:1371, doi: 10.1038/ncomms2394 (2013).

Seminar Organizer: Prof. Yoram Dagan