Researchers have shown for the first time that electrical signals can read magnetic information hidden inside a new class of materials called altermagnets, according to a study published in the journal Nature.
Altermagnets show no net magnetization, so their internal magnetic order produces no magnetic field and stays invisible from outside. The team built a nanoscale device that turns that hidden order into a spin current, a flow of electrons carrying magnetic information, and carries it to a detector.
The device used an altermagnet made of manganese silicide, known as Mn5Si3, to generate and detect the spin currents. The altermagnet and the detector sat just 300 nanometres apart, about one hundredth the thickness of a human hair, the researchers said.

Passing an electric current through the altermagnet changed how its electrons behaved, and the resulting spin current travelled through a metal conduit to the detector, where it produced a measurable electrical signal. The work was led by Jone Mencos of CIC nanoGUNE in Spain, working with teams in the Czech Republic, Germany and France.
The result confirms a prediction made a few years ago by research groups in the Czech Republic and Germany, Phys.org reported. The researchers say the advance could feed into new ways of storing and processing information, though they still need to make the devices work at room temperature and switch the magnetic order with low-energy pulses.
Source: Phys.org