Colloquium - Jairo Sinova (Johannes Gutenberg U. Mainz) - Emergence of a new non-relativistic magnetic class: the discovery of altermagnets

Jairo Sinova
November 1, 2022
3:45PM - 4:45PM
1080 Physics Research Building

Date Range
2022-11-01 15:45:00 2022-11-01 16:45:00 Colloquium - Jairo Sinova (Johannes Gutenberg U. Mainz) - Emergence of a new non-relativistic magnetic class: the discovery of altermagnets Emergence of a new non-relativistic magnetic class: the discovery of altermagnets Dr. Jairo Sinova Johannes Gutenberg University Mainz, Germany Location: 1080 Physics Research Building, Smith Seminar Room Faculty Host: Chris Hammel Abstract: Antiferromagnetic spintronics has been a very active research area of condensed matter in recent years. As we have learned how to manipulate antiferromagnets actively and their emergent topology, further surprises awaited. Turning off spin-orbit coupling, a new fresh view at the family of antiferromagnetic ordered systems reveals also an emergent new class, with properties characteristic of ferromagnets and antiferromagnets, as well as properties unique to itself. This third phase is characterized by compensated magnetic order and a spin-splitting momentum locking, suggesting its name altermagnetism. We show that this new phase is as abundant in nature as conventional ferromagnetism and antiferromagnetism. Its discovery as a distinct phase comes by using a non-relativistic spin-symmetry formalism which, counter to magnetic symmetries, delimits the phase uniquely. Material candidates ocurr in both three-dimensional and two-dimensional crystals, in diverse structural or chemistry types, and in conduction types covering the whole spectrum from insulators to superconductors. Altermagnets can have impact on prominent research areas, including spintronics, ultra-fast optics, neuromorphics, thermoelectrics, field-effect electronics, multiferroics, magnonics, valleytronics, magnetic topological matter, and unconventional superconductivity. References: [1] Libor Šmejkal, Jairo Sinova and Tomas Jungwirth, Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries, arXiv:2105.05820, PRX 2022 [2] Libor Šmejkal, Jairo Sinova and Tomas Jungwirth, Emerging research landscape of altermagnetism, arXiv:2204.10844; PRX 2022 [3] Zexin Feng, et al  Observation of the Anomalous Hall Effect in a Collinear Antiferromagnet arXiv:2002.08712; Nature Electronics 2022 [4] Libor Smejkal, et al, Anomalous Hall antiferromagnets, Nature Revies Materials 7, 482 (2022) [5] Libor Šmejkal, et al, Giant and Tunneling Magnetoresistance in Unconventional Collinear Antiferromagnets with Nonrelativistic Spin-Momentum Coupling, Phys. Rev. X 12, 011028 (2022) [6] Rafael González-Hernández, et al, Efficient Electrical Spin Splitter Based on Nonrelativistic Collinear Antiferromagnetism, Phys. Rev. Lett. 126, 127701 (2021) [7] Libor Šmejkal, Rafael González-Hernández, T. Jungwirth and J. Sinova, Crystal time-reversal symmetry breaking and spontaneous Hall effect in collinear antiferromagnet, Sci. Adv. 6, 23 (2020)   The colloquium can also be seen on Zoom:  https://osu.zoom.us/j/91292283159?pwd=Ryt1TUV2Z0NiZUIwWklRTE92WjZ1dz09 1080 Physics Research Building America/New_York public

Emergence of a new non-relativistic magnetic class: the discovery of altermagnets

Dr. Jairo Sinova
Johannes Gutenberg University Mainz, Germany

Location: 1080 Physics Research Building, Smith Seminar Room

Faculty Host: Chris Hammel

Abstract: Antiferromagnetic spintronics has been a very active research area of condensed matter in recent years. As we have learned how to manipulate antiferromagnets actively and their emergent topology, further surprises awaited. Turning off spin-orbit coupling, a new fresh view at the family of antiferromagnetic ordered systems reveals also an emergent new class, with properties characteristic of ferromagnets and antiferromagnets, as well as properties unique to itself. This third phase is characterized by compensated magnetic order and a spin-splitting momentum locking, suggesting its name altermagnetism. We show that this new phase is as abundant in nature as conventional ferromagnetism and antiferromagnetism. Its discovery as a distinct phase comes by using a non-relativistic spin-symmetry formalism which, counter to magnetic symmetries, delimits the phase uniquely. Material candidates ocurr in both three-dimensional and two-dimensional crystals, in diverse structural or chemistry types, and in conduction types covering the whole spectrum from insulators to superconductors. Altermagnets can have impact on prominent research areas, including spintronics, ultra-fast optics, neuromorphics, thermoelectrics, field-effect electronics, multiferroics, magnonics, valleytronics, magnetic topological matter, and unconventional superconductivity.

Sionva Image for talk

References:

[1] Libor Šmejkal, Jairo Sinova and Tomas Jungwirth, Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries, arXiv:2105.05820, PRX 2022

[2] Libor Šmejkal, Jairo Sinova and Tomas Jungwirth, Emerging research landscape of altermagnetism, arXiv:2204.10844; PRX 2022
[3] Zexin Feng, et al  Observation of the Anomalous Hall Effect in a Collinear Antiferromagnet

arXiv:2002.08712; Nature Electronics 2022

[4] Libor Smejkal, et al, Anomalous Hall antiferromagnets, Nature Revies Materials 7, 482 (2022)

[5] Libor Šmejkal, et al, Giant and Tunneling Magnetoresistance in Unconventional Collinear Antiferromagnets with Nonrelativistic Spin-Momentum Coupling, Phys. Rev. X 12, 011028 (2022)

[6] Rafael González-Hernández, et al, Efficient Electrical Spin Splitter Based on Nonrelativistic Collinear Antiferromagnetism, Phys. Rev. Lett. 126, 127701 (2021)

[7] Libor Šmejkal, Rafael González-Hernández, T. Jungwirth and J. Sinova, Crystal time-reversal symmetry breaking and spontaneous Hall effect in collinear antiferromagnet, Sci. Adv. 6, 23 (2020)

 

The colloquium can also be seen on Zoom:  https://osu.zoom.us/j/91292283159?pwd=Ryt1TUV2Z0NiZUIwWklRTE92WjZ1dz09