Student Seminar
Name: Mr. Afsar Reja
Title: An Introduction to Altermagnetism
Date & Time: Thursday, 25th April 2024 at 4.00 p.m.
Venue: Rajarshi Bhattacharya Memorial Lecture Hall, Chemical Sciences Building
Abstract:
Magnetic materials are mainly classified into two types: ferromagnets and antiferromagnets [1]. Ferromagnetic materials have a nonzero total magnetization and break the time-reversal symmetry, resulting in spin-split bands. On the other hand, antiferromagnetic materials exhibit zero total magnetization and spin degenerate bands. Recently, a new type of magnetism called “altermagnetism” has been discovered [2]. Altermagnets possess a subtle interplay of characteristics of both ferromagnets and antiferromagnets. They demonstrate spin-split band structures, like ferromagnets, but have zero total magnetization like antiferromagnets [3-5]. In this seminar, I will begin by introducing this new class of magnets. I will discuss the symmetry requirements for obtaining this phase. Next, I will delve into some of their fascinating properties including the crystal Hall effect. Finally, I will briefly present their potential applications.
References:
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Ashcroft, N.W. and Mermin, N.D., 1976. Solid state. Physics (New York: Holt, Rinehart and Winston) Appendix C.
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Šmejkal, L., González-Hernández, R., Jungwirth, T. and Sinova, J., 2020. Crystal time-reversal symmetry breaking and spontaneous Hall effect in collinear antiferromagnets. Science advances, 6(23), p.eaaz8809.
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Šmejkal, L., Sinova, J. and Jungwirth, T., 2022. Beyond conventional ferromagnetism and antiferromagnetism: A phase with nonrelativistic spin and crystal rotation symmetry. Physical Review X, 12(3), p.031042.
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Šmejkal, L., MacDonald, A.H., Sinova, J., Nakatsuji, S. and Jungwirth, T., 2022. Anomalous hall antiferromagnets. Nature Reviews Materials, 7(6), pp.482-496.
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Šmejkal, L., Sinova, J. and Jungwirth, T., 2022. Emerging research landscape of altermagnetism. Physical Review X, 12(4), p.040501.