arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2204.09094cond-mat.supr-con
收藏

KTaO3-based二维电子气的超流刚度

Superfluid stiffness of a KTaO3-based two-dimensional electron gas

S. Mallik, G. Ménard, G. Saïz, H. Witt, J. Lesueur, A. Gloter, L. Benfatto, M. Bibes, N. Bergeal

摘要:

在对LaAlO 3/SrTiO 3系统进行了近20年的研究之后,最近在(111)取向KTaO 3基异质结构中发现了超导二维电子气(2-DEG),这为氧化物界面研究领域注入了新的动力。然而,虽然这两个接口共享共同的属性,实验也表明两个系统之间的重要差异。在这里,我们报告的栅极可调超导2-DEG(111)取向的KTaO 3晶体的表面产生的简单溅射薄Al层。我们使用微波输运表明,(111)-KTaO 3 2-DEG表现出无节点超导序参量与间隙值显着大于预期的一个简单的BCS弱耦合极限模型。与二维性质的超导性相一致,我们证明了一个定义明确的Berezinsky-Kosterlitz-无边界类型的过渡,这是没有报道的SrTiO 3为基础的接口。我们的发现为基础科学提供了创新的视角,也为自旋轨道电子学和拓扑电子学等各种领域的器件应用提供了创新的视角。

英文摘要:

After almost twenty years of intense work on the celebrated LaAlO3/SrTiO3 system, the recent discovery of a superconducting two-dimensional electron gases (2-DEG) in (111)-oriented KTaO3-based heterostructures injects new momentum to the field of oxides interfaces. However, while both interfaces share common properties, experiments also suggest important differences between the two systems. Here, we report gate tunable superconductivity in 2-DEGs generated at the surface of a (111)-oriented KTaO3 crystal by the simple sputtering of a thin Al layer. We use microwave transport to show that (111)-KTaO3 2-DEGs exhibit a node-less superconducting order parameter with a gap value significantly larger than expected within a simple BCS weak-coupling limit model. Consistent with the two-dimensional nature of superconductivity, we evidence a well-defined Berezinsky-Kosterlitz-Thouless type of transition, which was not reported on SrTiO3-based interfaces. Our finding offers innovative perspectives for fundamental science but also for device applications in a variety of fields such as spin-orbitronics and topological electronics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑