News

A joint publication with Jairo Sinova  and Helen Gomonay about magnon generation in NiO/Pt films has been published in Nature communications.

They demonstrate the combined generation of broadband and narrowband magnons in thin films of NiO/Pt. They present two excitation processes which both lead to the emmision of THz signals. These results open new routes towards the development of fast opto-spintronic devices based on antiferromagnetic materials.

You can find the publication under nature.com/articles/s41467-023-37509-6.

A joint publication with Helen Gomonay about spintronics in insulating 3d metal oxides with antiferromagnetic coupling has been published in Applied Physics Letters.

They describe that antiferromagnetic transition metal oxides are an established and widely studied materials system in the context of spin-based electronics, commonly used as passive elements in exchange bias-based memory devices. Currently, major interest has resurged due to the recent observation of long-distance spin transport, current-induced switching, and THz emission. As a result, insulating transition metal oxides are now considered to be attractive candidates for active elements in future spintronic devices. They discuss some of the most promising materials systems and highlight recent advances in reading and writing antiferromagnetic ordering. This article aims to provide an overview of the current research and potential future directions in the field of antiferromagnetic insulatronics.

You can find the publication under Appl. Phys. Lett. 122, 080502 (2023).

A joint publication with Jairo Sinova and Libor Šmejkal about the growth pathways and structural properties of the manganese silicides has been published in Physical Review Materials.

They describe that the magnetically ordered phases of the ${\mathrm{Mn}}_5{\mathrm{Si}}_3$ crystal are proving to be prototypes for the study of the new fundamental spin physics related to the spontaneous breaking of the time-reversal symmetry despite a zero net magnetization. Here, they report on a route to grow epitaxial ${\mathrm{Mn}}_5{\mathrm{Si}}_3$ thin films on Si(111). The growth pathways and structural properties of the manganese silicides can be rationalized in terms of reactions maximizing the free-energy lowering rate. Moreover, they found that the magnetic and the magnetotransport properties can be used as an efficient tool to track both ${\mathrm{Mn}}_5{\mathrm{Si}}_3$ crystallinity and proportion in the deposited layers.

You can find the publication under Phys. Rev. Materials 7, 024416 (2023).

A joint publication with Helen Gomonay about antiferromagnetic hysteresis above the spin flop field has been published in Physical Review B.

They demonstrate that external magnetic fields change the magnetic anisotropy in the antiferromagnet CoO. THis is shown by measuring hysteresis curves for magnetic fields higher than the spin flop field. This behavior is shown to agree with the presence of the unquenched orbital momentum, which can play an important role in antiferromagnetic spintronics.

You can find the publication under PhysRevB.107.L060403.

A joint publication with Jairo Sinova and Libor Šmejkal about the spontaneous anomalous Hall effect in a magnetic semicoductor has been published in Physical Review Letters.

They observe a spontaneoeus anomalous Hall signal without external magnetic fields in the semiconductor MnTe. The anomalous Hall effect arises from an unconventional phase with strong time-reversal symmetry breaking and alternating spin polarization in real-space crystal structure and momentum-space electronic structure.

You can find the publication under PhysRevLett.130.036702

A joint publication with Helen Gomonay about  domains the canted antiferromagnet hematite has been published in Physical Review B.

They study the domain structure of hematite and the influence of destressing fields on the magnetic domain structure. They find fluctuating destressing fields throughout the sample which leads to locally varying effective anisotropies. This effect strongly distinguishes such canted antiferromagnets from collinear ones and gives a foundation for further studies.

You can find the publication under PhysRevB.106.224419.

A publication of Jairo Sinova, Libor Šmejkal and Thomas Jungwirth about altermagnetism, a new nonrelativistic magnetic phase has been published in Physical Review X.

A few month ago a new magnetic phase (altermagnetism) has been proposed. Altermagnets have zero net magnetization (like antiferromagnets) yet spin split electronic bands (like ferromagnets). This paper describes the theoretic framework and orders recent research in the emerging field.

You can find the publication under PhysRevX.12.040501