# Phonon limited mobility of the Dirac-Fermions in a three-dimensional Dirac semimetal Cd$_3$As$_2$

## TL;DR

This paper presents a theoretical model for phonon-limited mobility in 3D Dirac semimetal Cd$_3$As$_2$, highlighting the effects of screening, temperature, and electron density on mobility, and comparing with experimental data and conventional electron gases.

## Contribution

The study introduces a comprehensive analytical model for phonon-limited mobility in 3D Dirac semimetals, accounting for screening and different phonon regimes, and compares results with experimental data and traditional electron gases.

## Key findings

- Screening significantly enhances mobility.
- Optical phonons dominate at higher temperatures.
- Crossover temperature increases with electron density.

## Abstract

A theoretical model is presented for the phonon limited mobility of the Dirac-Fermion gas in a three-dimensional (3D) Dirac semimetal Cd$_3$As$_2$ considering scattering from both the acoustic and the optical phonons. Screening effects are taken into account and it is found that they lead to a significant enhancement of the mobility. Simple analytical equations and power laws are obtained in both the Bloch-Gruneisen and equipartition regimes. The dependence of mobility on the temperature $T$ and the electron density $n_e$ is investigated. It is found that optical phonon limited mobility $\mu_{op}$ dominates over the acoustic phonon limited mobility $\mu_{ap}$ in the higher temperature region. There is a crossover of $\mu_{ap}$ and $\mu_{op}$ and the crossover temperature $T_c$ shifts to higher value with increasing $n_e$. Our calculations of the mobility are in good agreement with the recent experimental data. Comparison is also made with the results in the conventional 3D electron gas in a degenerate semiconductor.

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Source: https://tomesphere.com/paper/1907.13165