A new magnetic material just shattered world records, promising computer memory that's 75 million percent more sensitive.
April 17, 2026
Original Paper
Spin-Valley-Mismatched Altermagnet for Giant Tunneling Magnetoresistance
arXiv · 2604.14776
The Takeaway
Magnetoresistance is how your hard drive reads data, and we usually celebrate gains of a few percent. This new 'altermagnet' setup achieved a jump of 75,000,000%—a number so big it sounds like a typo. This is made possible by a specific crystal structure that perfectly filters electron spins. If this can be scaled up, it means non-volatile memory that is virtually instant and uses almost zero power. Your phone could potentially store a lifetime of video and never need to be 'saved' again.
From the abstract
Altermagnet-based heterojunctions have demonstrated magnetoresistive effects in experiments, however, a predictive theoretical model for non-ferromagnetic structures has remained elusive. In this work, we develop a tunneling-based spin-transport theory that explicitly incorporates the transverse-wavevector ($\bf{k}_\|$)-dependent spin polarization of an altermagnet's transport channels, enabling the prediction of giant tunneling magnetoresistance (TMR). Based on the theory, we predict that the a