Topological materials host robust properties, unaffected by microscopic perturbations, owing to the global topological properties of the bulk electron system. Materials in which the topological invariant can be changed by easily tuning external parameters are especially sought after. Zirconium pentatelluride (ZrTe₅) is one of a few experimentally available materials that reside close to the boundary of a topological phase transition, allowing the switching of its invariant by mechanical strain. Here, we unambiguously identify a topological insulator–metal transition as a function of strain, by a combination of ab initio calculations and direct measurements of the local charge density. Our model quantitatively describes the response to complex strain patterns found in bubbles of few layer ZrTe₅ without fitting parameters, reproducing the mechanical deformation-dependent closing of the band gap observed using scanning tunneling microscopy. We calculate the topological phase diagram of ZrTe₅ and identify the phase at equilibrium, enabling the design of device architectures, which exploit the topological switching characteristics of the system.

由于体电子系统的全局拓扑特性，拓扑材料具有稳健的特性，不受微观扰动的影响。可以通过轻松调整外部参数来改变拓扑不变量的材料尤其受到追捧。五碲化锆 (ZrTe ₅ ) 是少数实验可用的材料之一，靠近拓扑相变的边界，允许通过机械应变切换其不变量。在这里，我们通过从头算计算和局部电荷密度的直接测量相结合，明确地将拓扑绝缘体-金属转变确定为应变的函数。我们的模型定量描述了对在几层 ZrTe _{5气泡中发现的复杂应变模式的响应}在没有拟合参数的情况下，再现了使用扫描隧道显微镜观察到的与机械变形相关的带隙闭合。_{我们计算了 ZrTe 5}的拓扑相图并确定了平衡相，从而能够设计利用系统拓扑开关特性的器件架构。