• SUTD researchers developed an all-electrical method to control spin-polarized currents using altermagnet bilayers, potentially replacing current methods requiring magnetic fields.
• The new method utilizes chromium sulphide (CrS) bilayers and electric fields to control electron spin direction at room temperature.
• Discovery of room-temperature altermagnetism in metallic oxide expands potential material options for spintronic devices, enabling broader application and integration with current tech.

The field of spintronics has received a boost with the development of an all-electrical method to control spin-polarized currents using altermagnets. Researchers at the Singapore University of Technology and Design (SUTD) have successfully demonstrated this control using bilayers of chromium sulphide (CrS), offering a tuneable, magnetic-free alternative to traditional methods. This breakthrough could lead to more efficient, faster, and compact spintronic devices. Simultaneously, experiments have revealed room-temperature altermagnetism with antisymmetric spin polarization in a metallic oxide, which further underscores the potential of altermagnets in spintronics.

• What: Development of all-electrical control of spin-polarized currents using altermagnets and the discovery of room-temperature altermagnetism in a metallic oxide.
• Who: Researchers at Singapore University of Technology and Design (SUTD); Rajib Sarkar at Institute of Solid State and Materials Physics, TU Dresden, Dresden, Germany
• When: Research published in April/May 2025; Altermagnets discovered in 2024.
• Where: Singapore University of Technology and Design (SUTD); Institute of Solid State and Materials Physics, TU Dresden, Dresden, Germany

The development of all-electrical control of spin-polarized currents using altermagnets represents a significant advancement in spintronics. Traditional spintronics relies on ferromagnetic materials and strong magnetic fields, which limit the miniaturization and efficiency of devices. The use of altermagnets and electric fields offers a pathway to overcome these limitations. The discovery of room-temperature altermagnetism in a metallic oxide further expands the possibilities for material selection and device design. This could enable the creation of more energy-efficient, compact, and versatile spintronic devices that can be integrated with existing semiconductor technology. Further research is needed to explore the properties of different altermagnets and optimize their performance for specific applications.

We have now shown that we can generate and reverse the spin direction of the electron current in an altermagnet made of two very thin layers of chromium sulphide (CrS) at room temperature using only an electric field.

The emergence of altermagnet-based spintronics, with its all-electrical control and room-temperature operation, holds great promise for revolutionizing memory and logic devices. The work by SUTD researchers on CrS bilayers, coupled with the discovery of altermagnetism in metallic oxides, paves the way for more efficient, compact, and versatile spintronic devices. Future research will focus on identifying and characterizing new altermagnets, optimizing device performance, and integrating these technologies with existing semiconductor infrastructure, bringing us closer to a future where spintronics plays a central role in computing.