Zhang J L, Guo C Y, Zhu X D, Ma L, Zheng G L, Wang Y Q, Pi L, Chen Y, Yuan H Q, Tian M L
Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory of the Chinese Academy of Sciences, Hefei 230031, Anhui, People's Republic of China.
Department of Physics and Center for Correlated Matter, Zhejiang University, Hangzhou 310027, Zhejiang, People's Republic of China.
Phys Rev Lett. 2017 May 19;118(20):206601. doi: 10.1103/PhysRevLett.118.206601.
We study the effect of hydrostatic pressure on the magnetotransport properties of zirconium pentatelluride. The magnitude of resistivity anomaly gets enhanced with increasing pressure, but the transition temperature T^{*} is insensitive to it up to 2.5 GPa. In the case of H∥b, the quasilinear magnetoresistance decreases drastically from 3300% (9 T) at ambient pressure to 230% (9 T) at 2.5 GPa. Besides, the change of the quantum oscillation phase from topological nontrivial to trivial is revealed around 2 GPa. Both demonstrate that the pressure breaks the accidental Dirac node in ZrTe_{5}. For H∥c, in contrast, subtle changes can be seen in the magnetoresistance and quantum oscillations. In the presence of pressure, ZrTe_{5} evolves from a highly anisotropic to a nearly isotropic electronic system, which accompanies the disruption of the accidental Dirac semimetal state. It supports the assumption that ZrTe_{5} is a semi-3D Dirac system with linear dispersion along two directions and a quadratic one along the third.
我们研究了静水压力对五碲化锆磁输运性质的影响。电阻率异常的幅度随压力增加而增强，但在高达2.5吉帕的压力下，转变温度T*对其不敏感。在H∥b的情况下，准线性磁电阻从常压下的3300%（9特斯拉）急剧下降到2.5吉帕时的230%（9特斯拉）。此外，在2吉帕左右发现量子振荡相位从拓扑非平凡转变为平凡。这两者都表明压力打破了ZrTe₅中的偶然狄拉克节点。相比之下，对于H∥c，磁电阻和量子振荡中可以看到细微变化。在有压力的情况下，ZrTe₅从高度各向异性的电子系统演变为几乎各向同性的电子系统，这伴随着偶然狄拉克半金属态的破坏。这支持了ZrTe₅是一个半三维狄拉克系统的假设，其在两个方向上具有线性色散，在第三个方向上具有二次色散。
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