KTaO₃-based nanoelectronic devices

The KTaO₃ (KTO)-based two dimensional electron gas (2DEG) has recently elicited wide interest in the field of oxide interfaces. Tantalum’s 5d electrons have a much stronger spin-orbit coupling compared to the titanium 3d orbital found in the extensively studied SrTiO₃ (STO) system. KTO (110)- and (111)-based heterostructures show superconductivity with a critical temperature near 1 K and 2 K, respectively [1,2], one order larger than the Tc of STO. Here we report reversible patterning of the 2DEG at the LAO/KTO interface using two techniques: (1) conductive atomic force microscope (c-AFM) lithography and (2) ultra low voltage electron beam lithography (ULV-EBL) [3]. The resolution of these two techniques can reach below 20 nm. Creation of nanoelectronic devices can provide insights into the pairing mechanism of KTO, and also enables KTO to be a potential platform for spintronics or quantum information applications.

[1] Liu, Changjiang, et al. Science 371.6530 (2021): 716-721.

[2] Chen, Zheng, et al. Physical Review Letters 126.2 (2021): 026802.

[3] Yu, Muqing, et al. Nano Lett. 22.15 (2022): 6062–6068