Two-Carrier Transport Induced Hall Anomaly and Large Tunable Magnetoresistance in Dirac Semimetal Cd3As2 Nanoplates

TL;DR

This study investigates the magnetotransport properties of Cd3As2 nanoplates, revealing two-carrier transport, a carrier-type transition influenced by temperature, and large tunable magnetoresistance, advancing understanding of Dirac semimetals.

Contribution

It provides detailed experimental insights into two-carrier transport and large magnetoresistance in Cd3As2 nanoplates, highlighting the role of temperature and gate voltage effects.

Findings

Observation of Hall anomaly indicating two-carrier transport.

Transition from n-type to p-type conduction with decreasing temperature.

Large non-saturating magnetoresistance up to 2000%.

Abstract

Cd3As2 is a model material of Dirac semimetal with a linear dispersion relation along all three directions in the momentum space. The unique band structure of Cd3As2 makes it with both Dirac and topological properties. It can be driven into a Weyl semimetal by the symmetry breaking or a topological insulator by enhancing the spin-orbit coupling. Here we report the temperature and gate voltage dependent magnetotransport properties of Cd3As2 nanoplates with Fermi level near the Dirac point. The Hall anomaly demonstrates the two-carrier transport accompanied by a transition from n-type to p-type conduction with decreasing temperature. The carrier-type transition is explained by considering the temperature dependent spin-orbit coupling. The magnetoresistance exhibits a large non-saturating value up to 2000% at high temperatures, which is ascribed to the electron-hole compensation in the system. Our results are valuable for understanding the experimental observations related to the two-carrier transport in Dirac/Weyl semimetals, such as Na3Bi, ZrTe5, TaAs, NbAs, and HfTe5.