Site web ESPCI
Jeudi 8 Novembre, 16h
Amphi Howleck, Esc C, 1ème etage
Magnetotransport and quantum oscillations at the LaAlO3/SrTiO3
heterointerface.
Alix McCollam
High Field Magnet Laboratory, Radboud University Nijmegen, The Netherlands.
Heterostructures of transition metal oxides offer many possibilities for multifunctional materials and device applications, as well as demonstrating new and complex fundamental properties [1-4]. Much of their potential stems from the possibility of interface properties that differ greatly from those of the bulk components, and the discovery of a 2-dimensional electron gas at the interface between band insulators LaAlO3 and SrTiO3[1] is an impor-
tant example of this. Understanding and controlling this 2D electron gas is currently one of the central problems in the field.
I will give a short introduction to the physics of oxide heterostructures, and then present the results of recent magnetotransport measurements of
the LaAlO3/SrTiO3 interface, performed at millikelvin temperatures and in magnetic fields of up to 30 T. Quantum oscillations observed in the resistivity allow us to probe the bandstructure of the interface electron gas, and give information about the band energies and the properties of the mobile charge carriers. The strong dependence of the oscillations on magnetic field, temperature, and orientation with respect to the plane of the interface, indicates a complex 2D system of closely-spaced electronic subbands, with different carrier effective masses and mobilities.