# Tunable Berry Curvature Through Magnetic Phase Competition in a Topological Kagome Magnet

## TL;DR

This study investigates how magnetic phase competition in the kagome magnet Co_3Sn_2S_2 influences its Berry curvature and topological properties, revealing tunable magnetic states and their effects on electronic behavior.

## Contribution

It demonstrates the presence of competing magnetic orders in Co_3Sn_2S_2 and shows how external magnetic field and pressure can tune these phases and the Berry curvature.

## Key findings

- Competing magnetic orders exist in Co_3Sn_2S_2.
- Magnetic phase competition affects anomalous Hall conductivity.
- External tuning controls magnetic phases and topological properties.

## Abstract

Magnetic topological phases of quantum matter are an emerging frontier in physics and material science. Along these lines, several kagome magnets have appeared as the most promising platforms. However, the magnetic nature of these materials in the presence of topological state remains an unsolved issue. Here, we explore magnetic correlations in the kagome magnet Co_3Sn_2S_2. Using muon spin-rotation, we present evidence for competing magnetic orders in the kagome lattice of this compound. Our results show that while the sample exhibits an out-of-plane ferromagnetic ground state, an in-plane antiferromagnetic state appears at temperatures above 90 K, eventually attaining a volume fraction of 80% around 170 K, before reaching a non-magnetic state. Strikingly, the reduction of the anomalous Hall conductivity above 90 K linearly follows the disappearance of the volume fraction of the ferromagnetic state. We further show that the competition of these magnetic phases is tunable through applying either an external magnetic field or hydrostatic pressure. Our results taken together suggest the thermal and quantum tuning of Berry curvature field via external tuning of magnetic order. Our study shows that Co_3Sn_2S_2 is a rare example where the magnetic competition drives the thermodynamic evolution of the Berry curvature field, thus tuning its topological state.