Strain flips Hall signal in altermagnetic manganese telluride, suggesting a path to practical spintronics

In a recent study published in Physical Review X, an international team of researchers led by Pengcheng Dai from Rice University observed a strain-sensitive quantum effect in an altermagnetic material known as hexagonal manganese telluride. This material is a promising candidate for practical spintronic devices due to its unique magnetic properties.

Unlike most magnets, hexagonal manganese telluride maintains low overall magnetization while exhibiting time-reversal symmetry, a behavior where the material's internal physics differs when running forward versus backward in time. However, this near-zero magnetization can complicate the isolation and control of magnetic effects.

To overcome this challenge, the researchers focused on the material's anomalous Hall effect, a sideways voltage generated by the material's internal magnetic structure that does not require an external field. By studying this effect and physically stretching the material, the team managed to reveal the true magnetic structure for the first time and discovered that strain could flip the sign of the Hall signal entirely.

Remarkably, a mere 1% change in strain had an effect comparable to a 150-degree temperature change, offering a more practical control method for real devices. This breakthrough provides researchers with a new way to manipulate magnetic effects in altermagnets, potentially leading to the development of strain-tunable sensors and spin-based electronic components that can operate at everyday temperatures.