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


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.


  1. Ashcroft, N.W. and Mermin, N.D., 1976. Solid state. Physics (New York: Holt, Rinehart and Winston) Appendix C.

  2. 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.
  3. 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.

  4. Šmejkal, L., MacDonald, A.H., Sinova, J., Nakatsuji, S. and Jungwirth, T., 2022. Anomalous hall antiferromagnets. Nature Reviews Materials, 7(6), pp.482-496.

  5.  Šmejkal, L., Sinova, J. and Jungwirth, T., 2022. Emerging research landscape of altermagnetism. Physical Review X, 12(4), p.040501.