Negative magnetoresistance suppressed through topological phase transition in (Cd1-xZnx)3As2 films

TL;DR

This study investigates how chemical substitution in (Cd1-xZnx)3As2 films suppresses negative magnetoresistance by inducing a topological phase transition from a Dirac semimetal to a trivial insulator, revealing the role of Berry curvature.

Contribution

It demonstrates the suppression of negative magnetoresistance through a topological phase transition controlled by Zn doping in (Cd1-xZnx)3As2 films.

Findings

Negative magnetoresistance decreases with Zn doping.

Berry curvature diminishes as the topological phase transitions.

Magnetotransport measurements distinguish chiral charge effects.

Abstract

The newly discovered topological Dirac semimetals host the possibilities of various topological phase transitions through the control of spin-orbit coupling as well as symmetries and dimensionalities. Here, we report a magnetotransport study of high-mobility (Cd1-xZnx)3As2 films, where the topological Dirac semimetal phase can be turned into a trivial insulator via chemical substitution. By high-field measurements with a Hall-bar geometry, magnetoresistance components ascribed to the chiral charge pumping have been distinguished from other extrinsic effects. The negative magnetoresistance exhibits a clear suppression upon Zn doping, reflecting decreasing Berry curvature of the band structure as the topological phase transition is induced by reducing the spin-orbit coupling.