论文标题
压力诱导的拓扑量子相变于Weyl Semimetal T_D-Mote_2
Pressure induced topological quantum phase transition in Weyl semimetal T_d-MoTe_2
论文作者
论文摘要
我们通过中子衍射实验报告了Weyl半分T_D-MOTE_2的晶体结构的压力（P_MAX = 1.5 GPA）。我们发现，基本的非中心对称结构T_D被完全抑制，并在p_cr = 1.2 GPA的临界压力下转化为中心质合1T结构。这是拓扑到微不足道电子状态之间压力引起的量子相变（QPT）的有力证据。尽管拓扑QPT对磁磁性具有很强的影响，但有趣的是，超导临界温度T_C，超流体密度和SC差距在P_CR中平稳而连续地变化，并且与T_D结构的抑制同时看到了突然的效果。这意味着T_C以及SC配对强度不受拓扑QPT的影响。但是，QPT要求SC间隙对称性从非平凡的S+变为微不足道的S ++状态，我们在这项工作中进行了讨论。我们对与拓扑QPT相关的结构和超导特性的系统表征，可深入了解此拓扑量子材料中压力引起的相图。
We report the pressure (p_max = 1.5 GPa) evolution of the crystal structure of the Weyl semimetal T_d-MoTe_2 by means of neutron diffraction experiments. We find that the fundamental non-centrosymmetric structure T_d is fully suppressed and transforms into a centrosymmertic 1T' structure at a critical pressure of p_cr = 1.2 GPa. This is strong evidence for a pressure induced quantum phase transition (QPT) between topological to a trivial electronic state. Although the topological QPT has strong effect on magnetoresistance, it is interesting that the superconducting critical temperature T_c, the superfluid density, and the SC gap all change smoothly and continuously across p_cr and no sudden effects are seen concomitantly with the suppression of the T_d structure. This implies that the T_c, and thus the SC pairing strength, is unaffected by the topological QPT. However, the QPT requires the change in the SC gap symmetry from non-trivial s+- to a trivial s++ state, which we discuss in this work. Our systematic characterizations of the structure and superconducting properties associated with the topological QPT provide deep insight into the pressure induced phase diagram in this topological quantum material.
