Topological Phase Transition in Single Crystals of $(Cd_{1-x} Zn_x)_3 As_2$

TL;DR

This study synthesizes and characterizes $(Cd_{1-x} Zn_x)_3 As_2$ single crystals, revealing a doping-controlled transition from a 3D Dirac semimetal to a semiconductor, offering a platform to explore topological quantum phase transitions.

Contribution

It demonstrates a chemical doping method to tune topological phases in $(Cd_{1-x} Zn_x)_3 As_2$, identifying a critical point and structural phase stability.

Findings

Transition from Dirac semimetal to semiconductor at x ≈ 0.38

Structural phase transitions are independent of topological change

Provides a tunable platform for topological quantum phase studies

Abstract

Single crystals of $(Cd_{1-x} Zn_x)_3 As_2$ were synthesized from high-temperature solutions and characterized in terms of their structural and electrical properties. Based on the measurements of resistivity and Hall signals, we revealed a chemical-doping-controlled transition from a three dimensional Dirac semimetal to a semiconductor with a critical point $x_c/sim 0.38$. We observed structural transitions from a body-center tetragonal phase to a primary tetragonal phase then back to a body-center tetragonal phase in the solid solutions as well, which are irrelevant to the topological phase transition. This continuously tunable system controlled by chemical doping provides a platform for investigating the topological quantum phase transition of 3D Dirac electrons.