Berry curvature-induced transport signature for altermagnetic order

Abstract Altermagnetism has been detected in several materials using spin-sensitive probes. These measurements require rather complex setups that make it challenging to track variations in altermagnetic order, e.g., to identify a temperature-tuned altermagnetic phase transition. We propose a simple...

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Main Authors: T. Farajollahpour, R. Ganesh, K. V. Samokhin
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:npj Quantum Materials
Online Access:https://doi.org/10.1038/s41535-025-00805-z
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author T. Farajollahpour
R. Ganesh
K. V. Samokhin
author_facet T. Farajollahpour
R. Ganesh
K. V. Samokhin
author_sort T. Farajollahpour
collection DOAJ
description Abstract Altermagnetism has been detected in several materials using spin-sensitive probes. These measurements require rather complex setups that make it challenging to track variations in altermagnetic order, e.g., to identify a temperature-tuned altermagnetic phase transition. We propose a simple transport measurement that can probe the order parameter for d-wave altermagnetism. We suggest magnetoconductivity anisotropy—the difference between the two principal values of the magnetoconductivity tensor. This quantity can be easily measured as a function of temperature, without any spin-selective apparatus. It acquires a nonzero value in a C 4 K phase, where C 4 rotations and time reversal K are not symmetries but their combination is. This effect can be traced to the modification of phase space density due to Berry curvature, which we demonstrate using semiclassical equations of motion for band electrons. As an illustration, we build a minimal tight-binding model with altermagnetic order that breaks C 4 and K symmetries while preserving C 4 K.
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spelling doaj-art-b82d185f3d4a4e4fa309095f406903e32025-08-20T03:42:30ZengNature Portfolionpj Quantum Materials2397-46482025-07-011011610.1038/s41535-025-00805-zBerry curvature-induced transport signature for altermagnetic orderT. Farajollahpour0R. Ganesh1K. V. Samokhin2Department of Physics, Brock UniversityDepartment of Physics, Brock UniversityDepartment of Physics, Brock UniversityAbstract Altermagnetism has been detected in several materials using spin-sensitive probes. These measurements require rather complex setups that make it challenging to track variations in altermagnetic order, e.g., to identify a temperature-tuned altermagnetic phase transition. We propose a simple transport measurement that can probe the order parameter for d-wave altermagnetism. We suggest magnetoconductivity anisotropy—the difference between the two principal values of the magnetoconductivity tensor. This quantity can be easily measured as a function of temperature, without any spin-selective apparatus. It acquires a nonzero value in a C 4 K phase, where C 4 rotations and time reversal K are not symmetries but their combination is. This effect can be traced to the modification of phase space density due to Berry curvature, which we demonstrate using semiclassical equations of motion for band electrons. As an illustration, we build a minimal tight-binding model with altermagnetic order that breaks C 4 and K symmetries while preserving C 4 K.https://doi.org/10.1038/s41535-025-00805-z
spellingShingle T. Farajollahpour
R. Ganesh
K. V. Samokhin
Berry curvature-induced transport signature for altermagnetic order
npj Quantum Materials
title Berry curvature-induced transport signature for altermagnetic order
title_full Berry curvature-induced transport signature for altermagnetic order
title_fullStr Berry curvature-induced transport signature for altermagnetic order
title_full_unstemmed Berry curvature-induced transport signature for altermagnetic order
title_short Berry curvature-induced transport signature for altermagnetic order
title_sort berry curvature induced transport signature for altermagnetic order
url https://doi.org/10.1038/s41535-025-00805-z
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