Non-Monotonic Evolution of Carrier Density and Mobility under Thermal Cycling Treatments in Dirac Semimetal Cd$_{3}$As$_{2}$ Microbelts
Zheng Chen1,2†, Min Wu1,2†, Yequn Liu3, Wenshuai Gao4, Yuyan Han1, Jianhui Zhou1*, Wei Ning1*, and Mingliang Tian1,4
1Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China 2Department of Physics, University of Science and Technology of China, Hefei 230026, China 3Analytical Instrumentation Center, State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China 4Department of Physics, School of Physics and Materials Science, Anhui University, Hefei 230601, China
Abstract：Tunable carrier density plays a key role in the investigation of novel transport properties in three-dimensional topological semimetals. We demonstrate that the carrier density, as well as the mobility, of Dirac semimetal Cd$_{3}$As$_{2}$ nanoplates can be effectively tuned via in situ thermal treatment at 350 K for one hour, resulting in non-monotonic evolution by virtue of the thermal cycling treatments. The upward shift of Fermi level relative to the Dirac nodes blurs the surface Fermi-arc states, accompanied by an anomalous phase shift in the oscillations of bulk states, due to a change in the topology of the electrons. Meanwhile, the oscillation peaks of bulk longitudinal magnetoresistivity shift at high fields, due to their coupling to the oscillations of the surface Fermi-arc states. Our work provides a thermal control mechanism for the manipulation of quantum states in Dirac semimetal Cd$_{3}$As$_{2}$ at high temperatures, via their carrier density.
2021, Vol. 38 
