Yu Muqing, Liu Changjiang, Yang Dengyu, Yan Xi, Du Qianheng, Fong Dillon D, Bhattacharya Anand, Irvin Patrick, Levy Jeremy
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States.
Pittsburgh Quantum Institute, Pittsburgh, Pennsylvania 15260, United States.
Nano Lett. 2022 Aug 10;22(15):6062-6068. doi: 10.1021/acs.nanolett.2c00673. Epub 2022 Jul 21.
Recent reports of superconductivity at KTaO (KTO) (110) and (111) interfaces have sparked intense interest due to the relatively high critical temperature as well as other properties that distinguish this system from the more extensively studied SrTiO (STO)-based heterostructures. Here, we report the reconfigurable creation of conducting structures at intrinsically insulating LaAlO/KTO(110) and (111) interfaces. Devices are created using two distinct methods previously developed for STO-based heterostructures: (1) conductive atomic-force microscopy lithography and (2) ultralow-voltage electron-beam lithography. At low temperatures, KTO(110)-based devices show superconductivity that is tunable by an applied back gate. A one-dimensional nanowire device shows single-electron-transistor (SET) behavior. A KTO(111)-based device is metallic but does not become superconducting. These reconfigurable methods of creating nanoscale devices in KTO-based heterostructures offer new avenues for investigating mechanisms of superconductivity as well as development of quantum devices that incorporate strong spin-orbit interactions, superconducting behavior, and nanoscale dimensions.
最近关于KTaO（KTO）（110）和（111）界面超导性的报道引发了强烈关注，这是由于其相对较高的临界温度以及其他特性，这些特性使该系统有别于研究更为广泛的基于SrTiO（STO）的异质结构。在此，我们报告了在本征绝缘的LaAlO/KTO（110）和（111）界面上可重构地创建导电结构。器件是使用先前为基于STO的异质结构开发的两种不同方法制造的：（1）导电原子力显微镜光刻法和（2）超低压电子束光刻法。在低温下，基于KTO（110）的器件表现出可通过施加背栅进行调节的超导性。一维纳米线器件表现出单电子晶体管（SET）行为。基于KTO（111）的器件是金属性的，但不会变成超导。这些在基于KTO的异质结构中创建纳米级器件的可重构方法为研究超导机制以及开发包含强自旋轨道相互作用、超导行为和纳米级尺寸的量子器件提供了新途径。
