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arXiv · 2412.13361

Two types of colossal magnetoresistance with distinct mechanisms in Eu5In2As6

Sudhaman Balguri·Mira B. Mahendru·Enrique O. Gonzalez Delgado·Kyle Fruhling·Xiaohan Yao·David E. Graf·Jose A. Rodriguez-Rivera·Adam A. Aczel·Andreas Rydh·Jonathan Gaudet·Fazel Tafti
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Abstract

Recent reports of colossal negative magnetoresistance (CMR) in a few magnetic semimetals and semiconductors have attracted attention, because these materials are devoid of the conventional mechanisms of CMR such as mixed valence, double exchange interaction, and Jahn-Teller distortion. New mechanisms have thus been proposed, including topological band structure, ferromagnetic clusters, orbital currents, and charge ordering. The CMR in these compounds has been reported in two forms: either a resistivity peak or a resistivity upturn suppressed by a magnetic field. Here we reveal both types of CMR in a single antiferromagnetic semiconductor Eu5In2As6. Using the transport and thermodynamic measurements, we demonstrate that the peak-type CMR is likely due to the percolation of magnetic polarons with increasing magnetic field, while the upturn-type CMR is proposed to result from the melting of a charge order under the magnetic field. We argue that similar mechanisms operate in other compounds, offering a unifying framework to understand CMR in seemingly different materials.

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Sudhaman Balguri, Mira B. Mahendru, Enrique O. Gonzalez Delgado, Kyle Fruhling, Xiaohan Yao, David E. Graf, Jose A. Rodriguez-Rivera, Adam A. Aczel, Andreas Rydh, Jonathan Gaudet, Fazel Tafti. 2024-12-17. Two types of colossal magnetoresistance with distinct mechanisms in Eu5In2As6. https://arxiv.org/abs/2412.13361

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