Abstract

We report on observation of superconducting current and AC Josephson effect in mesa-heterostructures with the interfaces comprised spin-singlet superconducting electrodes, coupled by a barrier made from strontium iridate, a material with the strong spin-orbit interaction. The superconducting critical current density was j_C ≈ 0.3 A/cm² at T = 4.2 K for mesa-heterostructures with d = 7 nm and j_C ≈ 4 A/cm² for d = 5 nm. The zero-bias conductance peak has been observed due to low energy states originated at Sr₂IrO₄/YBa₂Cu₃O_x interface. Under influence of weak magnetic field the critical current I_C(H) dependences showed Fraunhofer-like pattern indicating absence of pinholes, supported also by oscillating with microwave power Shapiro steps. Fiske resonance steps with voltage positions deviated from the ordinary ones were registered for mesas with d = 5 nm.

中文翻译：

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具有强自旋轨道相互作用的材料铱酸盐夹层的台面结构中的超导电流

摘要

我们报告观察到台面异质结构中的超导电流和AC约瑟夫森效应，其界面包括自旋单超导电极，再加上由具有强烈自旋轨道相互作用的材料铱铱酸盐制成的势垒。超导临界电流密度为Ĵ _Ç ≈0.3 A /厘米²在Ť = 4.2 K中台面异质与d = 7 nm和Ĵ _ç ≈4 A /厘米²为d = 5纳米。由于源自Sr ₂ IrO ₄ / YBa ₂ Cu ₃ O的低能态，已观察到零偏导流峰。_x接口。在弱磁场的影响下，临界电流I _C（ H）的依赖关系显示出Fraunhofer状的模式，表明不存在针孔，微波功率Shapiro阶跃也支持这种模式。电压位置偏离普通位置的菲斯克共振阶跃被记录为d = 5 nm的台面。