The study on quantum spin Hall effect and topological insulators formed the prologue to the surge of research activities in topological materials in the past decade. Compared to intricately engineered quantum wells, three-dimensional weak topological insulators provide a natural route to the quantum spin Hall effect, due to the adiabatic connection between them and a stack of quantum spin Hall insulators, and the convenience in exfoliation of samples associated with their van der Waals-type structure. Despite these advantages, both theoretical prediction and experimental identification of weak topological insulators remain scarce. Here, based on first-principles calculations, we show that AuTe₂Br locates at the boundary between a strong and a weak topological semimetal state. We identify the key structural parameter that dictates the traversal of the topological transition, which can be easily realized in experiments. More interestingly, the critical topology of AuTe₂Br persists up to an applied pressure of ~15.4 GPa before a structural phase transition accompanied by a change of electronic topology and the onset of superconductivity. Our results establish AuTe₂Br as a new candidate for an effective tuning between weak and strong topological phases in a single material, with the potential to realize various other topological phases of matter.

对量子自旋霍尔效应和拓扑绝缘体的研究，是近十年来拓扑材料研究活动激增的序幕。与复杂设计的量子阱相比，三维弱拓扑绝缘体为量子自旋霍尔效应提供了一条自然途径，这是由于它们与一堆量子自旋霍尔绝缘体之间的绝热连接，以及与其相关的样品剥离的便利性。范德华式结构。尽管有这些优势，但弱拓扑绝缘体的理论预测和实验识别仍然很少。在这里，基于第一性原理计算，我们证明了 AuTe ₂Br 位于强拓扑半金属态和弱拓扑半金属态的交界处。我们确定了决定拓扑转换遍历的关键结构参数，这可以在实验中轻松实现。更有趣的是，AuTe ₂ Br 的临界拓扑结构在伴随着电子拓扑结构变化和超导性开始的结构相变之前一直持续到~15.4 GPa 的施加压力。我们的结果将 AuTe ₂ Br 确立为在单一材料中在弱拓扑相和强拓扑相之间进行有效调谐的新候选者，并有可能实现物质的各种其他拓扑相。