Side Gate Tunable Josephson Junctions at the LaAlO3/SrTiO3 Interface

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• 作者：A. M. R. V. L. MonteiroD. J. Groenendijk ; N. MancaE. Mulazimoglu ; S. GoswamiYa. Blanter ; L. M. K. VandersypenA. D. Caviglia
• 刊名：Nano Letters
• 出版年：2017
• 出版时间：February 8, 2017
• 年：2017
• 卷：17
• 期：2
• 页码：715-720
• 全文大小：472K
• ISSN：1530-6992

文摘

Novel physical phenomena arising at the interface of complex oxide heterostructures offer exciting opportunities for the development of future electronic devices. Using the prototypical LaAlO₃/SrTiO₃ interface as a model system, we employ a single-step lithographic process to realize gate-tunable Josephson junctions through a combination of lateral confinement and local side gating. The action of the side gates is found to be comparable to that of a local back gate, constituting a robust and efficient way to control the properties of the interface at the nanoscale. We demonstrate that the side gates enable reliable tuning of both the normal-state resistance and the critical (Josephson) current of the constrictions. The conductance and Josephson current show mesoscopic fluctuations as a function of the applied side gate voltage, and the analysis of their amplitude enables the extraction of the phase coherence and thermal lengths. Finally, we realize a superconducting quantum interference device in which the critical currents of each of the constriction-type Josephson junctions can be controlled independently via the side gates.