Enhancing the reproducibility of high-mobility γ-Al2O3/SrTiO3 interfaces

For almost two decades, oxide-based two-dimensional electron gasses (2DEGs) have been intensively studied. While most studies focus on the LaAlO₃/SrTiO₃ interface, the oxide interface with the highest achieved charge carrier mobility, μ = 140 000 cm2V-1s-1 at 2K, is γ-Al₂O₃/SrTiO₃.[1] This is an attractive property as it allows for mean free path dependent quantum and spin-charge inter-conversion measurements[2], and has potential in applications such as high-frequency devices, transparent conductors, and thermoelectric materials.[3] Here, I will present our attempt to increase the reproducibility of high-mobility γ-Al₂O₃/SrTiO₃ 2DEGs using pulsed laser deposition.

References

[1] Y. Z. Chen, N. Bovet, F. Trier, D. V. Christensen, F. M. Qu, N. H. Andersen, T. Kasama, W. Zhang, R. Giraud, J. Dufouleur, T. S. Jespersen, J. R. Sun, A. Smith, J. Nygård, L. Lu, B. B¨uchner, B. G. Shen, S. Linderoth, and N. Pryds, Nature Communications 4, 1371 (2013).

[2] M. Oltscher, M. Ciorga, M. Utz, D. Schuh, D. Bougeard, and D. Weiss, Phys. Rev. Lett. 113, 236602 (2014).

[3] F. Trier, D. V. Christensen, and N. Pryds, Journal of Physics D: Applied Physics 51, 293002 (2018).