Phase transitions associated with magnetic-field induced topological orbital momenta in a non-collinear antiferromagnet

Sihao Deng; Olena Gomonay; Jie Chen; Gerda Fischer; Lunhua He; Cong Wang; Qingzhen Huang; Feiran Shen; Zhijian Tan; Rui Zhou; Ze Hu; Libor Šmejkal; Jairo Sinova; Wolfgang Wernsdorfer; Christoph Sürgers

doi:10.1038/s41467-024-45129-x

Phase transitions associated with magnetic-field induced topological orbital momenta in a non-collinear antiferromagnet

Nat Commun. 2024 Jan 27;15(1):822. doi: 10.1038/s41467-024-45129-x.

Authors

Sihao Deng^{1

2

3}, Olena Gomonay⁴, Jie Chen^{5

6}, Gerda Fischer⁷, Lunhua He^{8

9

10}, Cong Wang¹¹, Qingzhen Huang¹², Feiran Shen^{5

6}, Zhijian Tan^{5

6}, Rui Zhou¹³, Ze Hu¹⁴, Libor Šmejkal⁴, Jairo Sinova⁴, Wolfgang Wernsdorfer^{7

15}, Christoph Sürgers¹⁶

Affiliations

¹ Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China. dengsh@ihep.ac.cn.
² Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe, 76049, Germany. dengsh@ihep.ac.cn.
³ Spallation Neutron Source Science Center, Dongguan, 523803, China. dengsh@ihep.ac.cn.
⁴ Institut für Physik, Johannes Gutenberg Universität Mainz, 55128, Mainz, Germany.
⁵ Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
⁶ Spallation Neutron Source Science Center, Dongguan, 523803, China.
⁷ Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe, 76049, Germany.
⁸ Spallation Neutron Source Science Center, Dongguan, 523803, China. lhhe@iphy.ac.cn.
⁹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. lhhe@iphy.ac.cn.
¹⁰ Songshan Lake Materials Laboratory, Dongguan, 523808, China. lhhe@iphy.ac.cn.
¹¹ School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
¹² NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
¹³ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
¹⁴ Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, 100872, China.
¹⁵ Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, Karlsruhe, 76021, Germany.
¹⁶ Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe, 76049, Germany. christoph.suergers@kit.edu.

Abstract

Resistivity measurements are widely exploited to uncover electronic excitations and phase transitions in metallic solids. While single crystals are preferably studied to explore crystalline anisotropies, these usually cancel out in polycrystalline materials. Here we show that in polycrystalline Mn₃Zn_0.5Ge_0.5N with non-collinear antiferromagnetic order, changes in the diagonal and, rather unexpected, off-diagonal components of the resistivity tensor occur at low temperatures indicating subtle transitions between magnetic phases of different symmetry. This is supported by neutron scattering and explained within a phenomenological model which suggests that the phase transitions in magnetic field are associated with field induced topological orbital momenta. The fact that we observe transitions between spin phases in a polycrystal, where effects of crystalline anisotropy are cancelled suggests that they are only controlled by exchange interactions. The observation of an off-diagonal resistivity extends the possibilities for realising antiferromagnetic spintronics with polycrystalline materials.

Abstract

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