Recently, monolayer CoSb/SrTiO₃ has been proposed as a candidate harboring interfacial superconductivity in analogy with monolayer FeSe/SrTiO₃. Experimentally, while the CoSb-based compounds manifesting as nanowires and thin films have been realized on SrTiO₃ substrates, serving as a rich playground, their electronic structures are still unknown and yet to be resolved. Here, we have fabricated CoSb_1−x nanoribbons with quasi-one-dimensional stripes on SrTiO₃(001) substrates using molecular beam epitaxy and investigated the electronic structure by in situ angle-resolved photoemission spectroscopy. Straight Fermi surfaces without lateral dispersions are observed. CoSb_1−x/SrTiO₃ is slightly hole doped, where the interfacial charge transfer is opposite to that in monolayer FeSe/SrTiO₃. The spectral weight near the Fermi level exhibits power-law-like suppression and obeys a universal temperature scaling, serving as the signature of Tomonaga–Luttinger liquid (TLL) state. The obtained TLL parameter of ~0.21 shows the underlying strong correlations. Our results not only suggest CoSb_1−x nanoribbon as a representative TLL system but also provide clues for further investigations on the CoSb-related interface.

最近，单层CoSb/SrTiO ₃已被提议作为具有与单层FeSe/SrTiO ₃类比的界面超导性的候选者。实验上，虽然已经在 SrTiO ₃衬底上实现了表现为纳米线和薄膜的 CoSb 基化合物，作为一个丰富的游乐场，但它们的电子结构仍然未知，有待解决。在这里，我们使用分子束外延在 SrTiO ₃ (001) 衬底上制造了具有准一维条纹的CoSb _{1- x}纳米带，并通过原位角分辨光电光谱研究了电子结构。观察到没有横向色散的直费米面。CoSb _{1− x}/SrTiO ₃是轻微的空穴掺杂，其中界面电荷转移与单层FeSe/SrTiO _{3 中的}相反。费米能级附近的光谱权重表现出类似幂律的抑制，并遵循通用温度标度，作为 Tomonaga-Luttinger 液体 (TLL) 状态的特征。获得的~0.21 的 TLL 参数显示了潜在的强相关性。我们的结果不仅表明 CoSb _{1− x}纳米带是具有代表性的 TLL 系统，而且还为进一步研究 CoSb 相关界面提供了线索。