Aryal Niraj, Jin Xilian, Li Q, Tsvelik A M, Yin Weiguo
Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, USA.
State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
Phys Rev Lett. 2021 Jan 8;126(1):016401. doi: 10.1103/PhysRevLett.126.016401.
We use first-principles methods to demonstrate that, in ZrTe_{5}, a layered van der Waals material like graphite, atomic displacements corresponding to five of the six zone-center A_{g} (symmetry-preserving) phonon modes can drive a topological transition from a strong to a weak topological insulator with a Dirac semimetal state emerging at the transition, giving rise to a Dirac topology surface in the multidimensional space formed by the A_{g} phonon modes. This implies that the topological transition in ZrTe_{5} can be realized with many different settings of external stimuli capable of penetrating through the phonon-space Dirac surface without breaking the crystallographic symmetry. Furthermore, we predict that domains with effective mass of opposite signs can be created by laser pumping and will host Weyl modes of opposite chirality propagating along the domain boundaries. Studying phonon-space topology surfaces provides a new route to understanding and utilizing the exotic physical properties of ZrTe_{5} and related quantum materials.
我们使用第一性原理方法证明，在ZrTe₅（一种类似于石墨的层状范德华材料）中，对应于六个区中心A₉（保对称）声子模式中五个模式的原子位移，可驱动拓扑转变，从强拓扑绝缘体转变为弱拓扑绝缘体，在转变处出现狄拉克半金属态，从而在由A₉声子模式形成的多维空间中产生狄拉克拓扑表面。这意味着ZrTe₅中的拓扑转变可以通过许多不同的外部刺激设置来实现，这些刺激能够穿透声子空间狄拉克表面而不破坏晶体对称性。此外，我们预测，通过激光泵浦可以产生具有相反符号有效质量的畴，并且这些畴将承载沿畴边界传播的相反手性的外尔模式。研究声子空间拓扑表面为理解和利用ZrTe₅及相关量子材料的奇异物理性质提供了一条新途径。
