Computers, smartphones and data centers of the future could become faster and more efficient while reducing energy consumption. An important step toward achieving this goal comes from a discovery in the field of magnetism to which the University of Milano-Bicocca also contributed. The group from the Department of Materials Science, led by Professor Silvia Picozzi, has in fact identified a new material, nickel iodide, which belongs to a recently discovered class of materials: that of altermagnets. The study, carried out in collaboration with the Massachusetts Institute of Technology (MIT) in Boston, was published in Nature, among the most authoritative international scientific journals. The classical theory of magnetism distinguishes two main categories of materials: ferromagnets, such as common magnets, and antiferromagnets. The former are easy to control, but not miniaturizable below a certain limit; the latter are more stable, fast and immune to so-called “parasitic magnetic fields”, but difficult to manipulate because they lack net magnetization. In 2022, a third form of magnetic behavior was identified: altermagnetism. Altermagnets behave in a novel way, allowing the limitations of both traditional classes to be overcome. In these materials, although there is no overall magnetization, electronic states with opposite spins have different energies. This property allows for more effective and precise control of magnetic behavior. Given the potential relevance in technology, altermagnetism has been included by the journal Science among the major scientific discoveries of 2024, the only entry in the field of physics. The possibility of using these materials in spintronics - electronics that exploits electron spin rather than charge alone - opens concrete scenarios for the development of devices that are more precise, faster, miniaturizable, and have very low power consumption. In the project, the University of Milan-Bicocca group handled the theoretical development and numerical simulations, while the MIT team conducted the physical characterization of the material. Nickel iodide is an important model system for the study of altermagnets, but it currently requires very low temperatures to express its magnetic properties and is not yet usable in real devices. The next step, therefore, will be to use the knowledge gained to design new altermagnetic materials that are stable at room temperature, with the goal of making it possible to make low-power, very high-performance electronic devices.