Topological superconductors (TSC) can host exotic quasiparticles such as Majorana fermions, poised as the fundamental qubits for quantum computers. TSC’s are predicted to form a superconducting gap in the bulk, and gapless surface/edges states which can lead to the emergence of Majorana zero energy modes. A candidate TSC is the layered dichalcogenide MoTe₂, a type-II Weyl (semi)metal in the non-centrosymmetric orthorhombic (T_d) phase. It becomes superconducting upon cooling below 0.25 K, while under pressure, superconductivity extends well beyond the structural boundary between the orthorhombic and monoclinic (1T′) phases. Here, we show that under pressure, coupled with the electronic band transition across the T_d to 1T′ phase boundary, evidence for a new phase, we call T_d* is observed and appears as the volume fraction of the T_d phase decreases in the coexistence region. T_d* is most likely centrosymmetric. In the region of space where T_d* appears, Weyl nodes are destroyed. T_d* disappears upon entering the monoclinic phase as a function of temperature or on approaching the suppression of the orthorhombic phase under pressure above 1 GPa. Our calculations in the orthorhombic phase under pressure show significant band tilting around the Weyl nodes that most likely changes the spin-orbital texture of the electron and hole pockets near the Fermi surface under pressure that may be linked to the observed suppression of magnetoresistance with pressure.

拓扑超导体（TSC）可以容纳奇异的准粒子，例如马约拉那费米子，它们准备作为量子计算机的基本量子位。预计TSC会在整体中形成超导间隙，并且无间隙的表面/边缘状态会导致Majorana零能量模式的出现。候选TSC是层状二硫化_二钼MoTe ₂，这是非中心对称正交（T _d）相中的II型Weyl（半）金属。在冷却到0.25 K以下时，它变得超导，而在压力下，超导性远远超出了正交晶和单斜（1T'）相之间的结构边界。在这里，我们显示出在压力下，以及跨T _d的电子能带跃迁到1T'相界，发现了一个新相的证据，我们称T _d *并随着共存区域中T _d相体积分数的减少而出现。T _d *很可能是中心对称的。在出现T _d *的空间区域中，Weyl节点被破坏。Ť _d*在进入单斜晶相时随温度变化或在压力高于1 GPa时接近斜方晶相的抑制而消失。我们在斜方晶相在压力下的计算表明，在Weyl节点周围有明显的能带倾斜，这很可能会改变在费米表面附近电子和空穴在费米表面附近的自旋轨道结构，这可能与观察到的压力对磁阻的抑制有关。