January 2018

Researchers from Mainz University demonstrate the basic principles of ultra-fast and stable memory based on the antiferromagnet Mn₂Au. Antiferromagnetic materials are challenging to manipulate and to implement a read-out process (of the Neel vector orientation on).

Up until now, researchers were only able to use a single antiferromagnetic material - copper manganese arsenide (CuMnAs), but this material had several disadvantages. The new compound, manganese and gold (Mn₂Au) offers for example ten times larger magnetoresistance and other important advantages including its non-toxic composition and the fact that it can be used even at higher temperatures.

Researchers from the NIST in the US and the University of Tokyo have discovered a metallic antiferromagnet (Mn₃Sn) that exhibits a large magneto-optic Kerr (MOKE) effect, despite a vanishingly small net magnetization at room temperature.

Compared to ferromagnetic materials, metallic antiferromagnets allow for faster dynamics and more densely packed spintronic devices due to the weak interactions between antiferromagnetic cells. The researchers believe that such materials hold promise for future antiferromagnetic spintronic devices, where the magnetic state could transduced optically and switched either optically or by applying current.

Reseaerchers from TU Delft developed a method to convert the spin information into light signals at room temperature. The researchers hope that this method could enable opto-spintronics devices.

The researchers used a device made from a thin silver thread and a 2D tungsten disulfide film on top. Using circularly polarised light, the researchers created excitons with a specific rotational direction (that could be intitialized using the rotational direction of the laser light). The excitons emit photons when they relax. And the emitted light contains the spin information.

Researchers at UC Riverside have determined the strength of the electron spin interactions with the optical phonons in antiferromagnetic nickel oxide (NiO) crystals. The researchers say that Nio is a promising spintronics materials and the the strength of the electron spin interaction with phonons is important for future device development.

The researcher say that NiO has been studied for many years, but not fully understood. The new research used novel techniques to finally shed light on some of the long-standing puzzles surrounding this material.