Memory That Stays Cool express
An ordinary flash drive in your pocket gets warm even when it's just sitting there. Now imagine memory that, in the cold, uses almost nothing, like a thermos that never cools down. A superconductor carries current without loss at liquid-helium temperatures, but it couldn't store data. The new cell changes that.
Inside is a layered sandwich of niobium and magnetic films. A magnetic field shifts the superconductor's energy gap, and the tunneling current through the barrier changes. This yields two clear voltage levels — zero and one.
Such memory is needed right next to quantum processors: ordinary electronics introduce heat and noise. Here, the design is vertical, like a stack of pancakes, which can be printed by the millions on a single wafer. A quantum computer gets a fast, cold "notebook."
Original abstract
as written by the authors arXiv:2604.22214
Scalable, low-dissipation memory operating below 4 K is a critical requirement for superconducting and quantum computing systems. Existing cryogenic memory technologies rely on CMOS derivatives or hybrid architectures that incur leakage, refresh overhead or limited compatibility with superconducting logic. Here we demonstrate a superconducting tunnelling magnetoresistance device that functions as a non-volatile cryogenic memory element across the full superconducting temperature range. By integrating a de Gennes spin valve with a superconducting tunnel junction in a current perpendicular-to-plane geometry, we realise exchange-field control of the superconducting energy gap. This produces two magnetically switchable gap voltages and robust quasiparticle tunnelling magnetoresistance down to 0.25 K.The device operates at millivolt bias with nanowatt-level read power and zero standby dissipation. Its vertical junction architecture and Nb-based materials platform enable compatibility with superconducting logic and scalable cryogenic memory arrays.
At 0.25 kelvin (that's minus 272.9 degrees Celsius), even helium stays liquid, and the device still clearly distinguishes zero from one.