Dennis V. Christensen, Department of Energy Conversion and Storage, Technical University of Denmark: Coexistence of high electron mobility, colossal magnetoresistance and magnetism at the γ-Al2O3/SrTiO3 heterointerface

31.08.2017 15:00 – 16:30

The plethora of fascinating properties observed in oxide heterostructures has attracted a lot of interest. Most noticeably, the confined electron gas formed at the interface between the two insulators LaAlO3 and SrTiO3 features e.g. gate-tunable superconductivity, ferromagnetism and non-volatile memory effects. Numerous studies have been devoted to understanding the origin of the conductivity along with enhancing its properties. Recently, we found that substituting LaAlO3 with γ-Al2O3 can produce a confined electron gas with an electron mobility exceeding 100,000 cm2/Vs. Here, I show that the γ-Al2O3/SrTiO3 interface conductivity originates from oxygen vacancies and use defect engineering to control various interface properties. In addition, I find that the high mobility coexists with a strain-tunable magnetic order below 40 K and a positive, non-saturating magnetoresistance of up to 80,000% at 15 T. The study evidences that the γ-Al2O3/SrTiO3 heterostructure is an exciting alternative to LaAlO3/SrTiO3 and paves the way for combining lattice, spin and electronic degrees of freedom.


Bâtiment: Ecole de Physique

MaNEP conference room

Organisé par

Département de physique de la matière quantique

entrée libre


Catégorie: Séminaire

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