Magnetic order without a magnet.
Room-temperature antiferromagnetic semiconductors are a serious material-science frontier, not instant terahertz computers.
What has been observed
Bulk NaMnAs is an antiferromagnetic semiconductor. A July 2026 Physical Review B experiment reports an antiferromagnetic resonance observable up to room temperature. That does not by itself establish manufacturable nonvolatile memory or consumer processors.
What an altermagnet might change
Spin-selective electronic structure without ordinary ferromagnetic net magnetization raises intriguing approaches to readout, logic and memory. Integration, switching energy, yields and stability remain formidable tests.
A diode is not the grid
Perfect superconducting-diode efficiency describes directional critical-current asymmetry in a specified model; it is not an efficiency claim for a power transmission system. Cooling, AC losses, contacts, protection and power conversion still exist.
Neuromorphic ≠zero-energy intelligence
Nonvolatile states can reduce standby losses. Sensing, state changes, interconnects and inference still consume energy. No published result here warrants a claim that a 400-billion-parameter model could operate from ambient static electricity.