近年来拓扑半金属成为凝聚态物理领域研究的热点。最近出现的ZrTe5材料已经被实验证实是三维的Dirac半金属（DSM）。而在已经开展的实验研究中尚无极端强磁场下的输运特性的报道，特别是当系统的费米能级进入朗道能级n=1（量子极限）甚至n=0 (超量子极限)后的一些输运特性。我们的初步测量结果表明，层状材料ZrTe5在弱的磁场下就能驱动费米能级到达量子极限。这使得层状材料ZrTe5成为研究量子极限，甚至超量子极限条件下三维DSM输运特性的理想平台之一。而且，层状结构的ZrTe5易于制备成场效应器件，在同时受磁场和电场的调控下，时间反演对称性和空间反转对称性被破坏，使Dirac点在动量和能量空间中分离为两个Weyl点。从而可以开展理论预言的反常霍尔效应以及磁单极子等新奇量子现象的探索研究。该项目将以DSM材料为研究对象，系统研究其在强磁场下和受背栅调控的输运特性。

In recent years, topological semi-metal has attracted much attentions due to their exotic transport properties. ZrTe5 had been proved to be three-dimensional Dirac semi-metal (DSM) by recent experiments. However, the quantum transport properties of DSM under intense strong magnetic field is still lacking so far. Especially when the Fermi level of the system enters into the first Landau level n=1 (quantum limit) or n = 0 (ultra-quantum limit). Our previous experiments show that under a moderate magnetic field, the Fermi level of ZrTe5 can be driven to the quantum limit, revealing that ZrTe5 is an ideal platform to study the quantum transport properties of DSM under quantum limit or ultra-quantum limit. Moreover, due to its layered structure in ZrTe5, field effect device can be easily fabricated and controlled by both magnetic and electric fields. Thus, both time-reversal symmetry and spatial inversion symmetry can be broken, leading to a transformation from the Dirac semimetal to a Weyl semimetal. Thereby, we can explorer the theoretical predicted anomalous Hall effect as well as magnetic monopoles experimentally. This project, combining the back-gate techniques, will study the new quantum transport phenomenon of DSM under an intense magnetic field.