Investigation of the Effect of capping on the Dirac semimetal Cd3As2 on Si grown via molecular beam epitaxy

Wei-Chen Lin¹, Chiashain Chuang^2*, Chun-Wei Kuo², Meng-Ting Wu², Jie-Ying Lee³, Hsin-Hsuan Lee⁴, Cheng-Hsueh Yang³, Ji-Wei Ci², Tian-Shun Xie⁵, Nobuyuki Aoki⁵, Chi-Te Liang³

¹Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg/Maryland, USA
²Department of Electronic Engineering, Chung Yuan Christian University, Taoyuan, Taiwan
³Department of Physics, National Taiwan University, Taipei, Taiwan
⁴Department of Physics, Chung Yuan Christian University, Taoyuan, Taiwan
⁵Department of Materials Science, Chiba University, Chiba, Japan

* Presenter:Chiashain Chuang, email:chiashain@cycu.edu.tw

In this talk, I would present the promising applications of large magnetoresistance in the Dirac semimetal cadmium arsenide, a series of research regarding Cd3As2 grown on silicon substrates is highly desirable. In this study, two insulating protection materials with different preparation methods were separately covered on top of two Cd3As2 samples which were both grown on silicon substrates. An additional zinc telluride (ZnTe) layer was grown on the surface of the Cd3As2 device, and we observed a remarkable enhancement in mobility, surpassing that of the pristine Cd3As2 sample by an order of magnitude. Surprisingly, an unusual negative magnetoresistance behaviour was observed on the drily transferred hexagonal boron nitride-capped Cd3As2 heterostructure sample in a perpendicular magnetic field which is different from the chiral anomaly that requires a parallel magnetic field. Our work suggests that capping MBE-grown Cd3As2 on Si, which is fully compatible with Si CMOS technology, can be advantageous for device applications.

Keywords: Dirac semimetal, Cd3As2, h-BN, Topological materials , Two-dimensional materials