论文标题
I型Weyl半学的光导率的两个线性状态：元素柜面的情况
Two linear regimes in optical conductivity of a Type-I Weyl semimetal: the case of elemental tellurium
论文作者
论文摘要
采用高压红外光谱法，我们揭示了元素TE的Weyl半准相及其拓扑特性。光导率的线性频率依赖性为三角矫治（TE-I）和3.0 GPA高于3.0 GPA的线性带分散的金属化提供了明确的证据。这种半金属WEYL相可以通过进一步的压力来调节：扭结在光导率（3.7 GPa）中分离了两个线性状态，这是针对倾斜锥的II型Weyl半学的签名；然而，这揭示了三角矫治的起源不同。我们的密度功能计算并未显示出任何明显的倾斜度，并表明Te-I仍处于I型Weyl相中，但有两个价带，是费米水平的附近。它们的相互作用引起了多个线性状态的特殊光学电导率行为。高于4.3 GPA的压力使更复杂的TE-II和TE-III多晶型物稳定，这是强大的金属。
Employing high-pressure infrared spectroscopy we unveil the Weyl semimetal phase of elemental Te and its topological properties. The linear frequency dependence of the optical conductivity provides clear evidence for metallization of trigonal tellurium (Te-I) and the linear band dispersion above 3.0 GPa. This semimetallic Weyl phase can be tuned by increasing pressure further: a kink separates two linear regimes in the optical conductivity (at 3.7 GPa), a signature proposed for Type-II Weyl semimetals with tilted cones; this however reveals a different origin in trigonal tellurium. Our density-functional calculations do not reveal any significant tilting and suggest that Te-I remains in the Type-I Weyl phase, but with two valence bandsin the vicinity of the Fermi level. Their interplay giving rise to the peculiar optical conductivity behavior with more than one linear regime. Pressure above 4.3 GPa stabilizes the more complex Te-II and Te-III polymorphs, which are robust metals.
