Top-gated field-effect LaAlO 3 /SrTiO 3 devices made by ion-irradiation

S. Hurand (1) , A. Jouan (1) , C. Feuillet-Palma (1) , G. Singh (1) , E. Lesne (2) , N. Reyren (2) , A. Barthélémy (2) , M. Bibes (2) , J. Villegas (2) , C. Ulysse (3) , M. Pannetier-Lecoeur (4) , M. Malnou (1) , J. Lesueur (1) , N. Bergeal (1)

1 LPEM - Laboratoire de Physique et d'Etude des Matériaux (UMR 8213)
2 Laboratoire Albert Fert (ex-UMPhy Unité mixte de physique CNRS/Thales)
3 LPN - Laboratoire de photonique et de nanostructures
4 LNO - Laboratoire Nano-Magnétisme et Oxydes

We present a method to fabricate top-gated field-effect devices in a LaAlO3/SrTiO3 two-dimensional electron gas (2-DEG). Prior to the gate deposition, the realisation of micron size conducting channels in the 2-DEG is achieved by an ion-irradiation with high-energy oxygen ions. After identifying the ion fluence as the key parameter that determines the electrical transport properties of the channels, we demonstrate the field-effect operation. At low temperature, the normal state resistance and the superconducting Tc can be tuned over a wide range by a top-gate voltage without any leakage. A superconductor-to-insulator quantum phase transition is observed for a strong depletion of the 2-DEG.

Domaines: Matière Condensée [cond-mat]

S. Hurand, A. Jouan, C. Feuillet-Palma, G. Singh, E. Lesne, et al.. Top-gated field-effect LaAlO 3 /SrTiO 3 devices made by ion-irradiation. Applied Physics Letters, 2016, 108 (5), pp.052602. ⟨10.1063/1.4941672⟩. ⟨cea-03106328⟩