Experimental signatures of versatile Weyl semimetal in pyrochlore iridate with spin-ice like magnetic orders

TL;DR

This paper presents experimental evidence of topological phase transitions in a pyrochlore Weyl semimetal, influenced by magnetic orders, Kondo coupling, and pressure, revealing potential for engineering band topology in quantum materials.

Contribution

It demonstrates how magnetic field, pressure, and Kondo coupling affect Weyl semimetal states and topological transitions in Pr2Ir2O7, a hybrid quantum material.

Findings

Resistivity and Hall conductivity show a plateau and sharp jump with magnetic hysteresis.

Hydrostatic pressure controls Kondo coupling and Weyl point displacement.

Field-induced topological transitions depend on electronic state and magnetic interactions.

Abstract

We report experimental signatures of topological transitions among the Weyl semimetal states of pyrochlore Pr2Ir2O7, where the Kondo coupling between the Ir topological electrons and the spin-ice like orders of Pr moments plays a decisive role. The magnetic-field dependence of resistivity and the Hall conductivity exhibits a plateau and a sharp jump associated with a magnetic-field hysteresis, similar to a liquid-gas-like transition in dipolar spin ice system. Furthermore, the Kondo coupling is controlled by the hydrostatic pressure, revealing that the field-induced displacement of Weyl points in the momentum space strongly depends on the respective electronic state as well as on the Kondo coupling strength. These observations pave a route toward the engineering of band topology in hybrid quantum materials with relativistic conduction electrons and localized magnetic moments.