Erlandsen Ricci, Dahm Rasmus Tindal, Trier Felix, Scuderi Mario, Di Gennaro Emiliano, Sambri Alessia, Reffeldt Kirchert Charline Kaisa, Pryds Nini, Granozio Fabio Miletto, Jespersen Thomas Sand
Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej, Building 310, 2800 Kgs. Lyngby, Denmark.
Institute for Microelectronics and Microsystems (CNR-IMM), Strada VIII n.5 Zona Industriale, I-95121 Catania, Italy.
Nano Lett. 2022 Jun 22;22(12):4758-4764. doi: 10.1021/acs.nanolett.2c00992. Epub 2022 Jun 9.
Freestanding oxide membranes constitute an intriguing material platform for new functionalities and allow integration of oxide electronics with technologically important platforms such as silicon. Sambri et al. recently reported a method to fabricate freestanding LaAlO/SrTiO (LAO/STO) membranes by spalling of strained heterostructures. Here, we first develop a scheme for the high-yield fabrication of membrane devices on silicon. Second, we show that the membranes exhibit metallic conductivity and a superconducting phase below ∼200 mK. Using anisotropic magnetotransport we extract the superconducting phase coherence length ξ ≈ 36-80 nm and establish an upper bound on the thickness of the superconducting electron gas ≈ 17-33 nm, thus confirming its two-dimensional character. Finally, we show that the critical current can be modulated using a silicon-based backgate. The ability to form superconducting nanostructures of LAO/STO membranes, with electronic properties similar to those of the bulk counterpart, opens opportunities for integrating oxide nanoelectronics with silicon-based architectures.
独立氧化物膜构成了一个用于实现新功能的有趣材料平台，并允许将氧化物电子器件与诸如硅等具有重要技术意义的平台集成。桑布里等人最近报道了一种通过应变异质结构剥落来制备独立的镧铝氧/钛酸锶（LAO/STO）膜的方法。在此，我们首先开发了一种在硅上高产率制造膜器件的方案。其次，我们表明这些膜在低于约200 mK时表现出金属导电性和超导相。利用各向异性磁输运，我们提取出超导相干长度ξ≈36 - 80 nm，并确定了超导电子气厚度的上限≈17 - 33 nm，从而证实了其二维特性。最后，我们表明临界电流可以通过基于硅的背栅进行调制。形成具有与体材料类似电子特性的LAO/STO膜超导纳米结构的能力，为将氧化物纳米电子器件与基于硅的架构集成开辟了机会。
