The unique electronic structure found at interfaces between materials can allow unconventional quantum states to emerge. Here we report on the discovery of superconductivity in electron gases formed at interfaces between (111) oriented KTaO3 and insulating overlayers of either EuO or LaAlO3 The superconducting transition temperature, approaching 2.2 K, is about one order of magnitude higher than that of the LaAlO3/SrTiO3 system. Strikingly, similar electron gases at KTaO3 (001) interfaces remain normal down to 25 mK. The critical field and current-voltage measurements indicate that the superconductivity is two dimensional. In EuO/KTaO3 (111) samples, a spontaneous in-plane transport anisotropy is observed prior to the onset of superconductivity, suggesting the emergence of a distinct 'stripe' like phase, which is also revealed near the critical field.

中文翻译：

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KTaO3 (111) 界面的二维超导性和各向异性输运

在材料之间的界面处发现的独特电子结构可以允许出现非常规的量子态。在这里，我们报告了在 (111) 取向的 KTaO3 和 EuO 或 LaAlO3 绝缘覆盖层之间形成的电子气中超导性的发现。超导转变温度接近 2.2 K，比 LaAlO3/ SrTiO3 系统。引人注目的是，KTaO3 (001) 界面处的类似电子气在低至 25 mK 时仍保持正常。临界场和电流电压测量表明超导性是二维的。在 EuO/KTaO3 (111) 样品中，在超导性开始之前观察到自发的面内输运各向异性，表明出现了明显的“条纹”状相，