In a paper recently published in Nature Electronics, we show that a quantum point contact can be formed in a LaAlO3/SrTiO3 interface through electrostatic confinement of the 2-DEG using a split gate. Our device exhibits a quantized conductance due to ballistic transport in a controllable number of one-dimensional conducting channels. Under a magnetic field, the direct observation of the Zeeman splitting between spin-polarized bands allows the determination of the Landé g-factor, whose value differs strongly from that of the free electrons. Through source–drain voltage measurements, we also performed a spectroscopic investigation of the 3d energy levels inside the quantum point contact. The LaAlO3/SrTiO3 quantum point contact could potentially be used as a spectrometer
to probe Majorana states in an oxide 2-DEG.
This work was performed in collaboration with the LPEM lab of ESPCI in Paris, the C2N in Paris-Saclay and the CNR-SPIN lab in Naples.
Quantized conductance in a one-dimensional ballistic oxide nanodevice
A. Jouan, G. Singh , E. Lesne, D. C. Vaz, M. Bibes , A. Barthélémy, C. Ulysse,
D. Stornaiuolo, M. Salluzzo, S. Hurand , J. Lesueur, C. Feuillet-Palma and N. Bergeal
Nature Electron. https://doi.org/10.1038/s41928-020-0383-2 (2020)