Let's agree on the bar: real devices need reproducible, peer-reviewed results, not hype. That's fair. But altermagnets clear a genuine physics hurdle. They show spin-split electronic bands with zero net magnetization, so you get ferromagnet-like spin control without stray fields, plus antiferromagnet-like speed and stability. That combination is rare and directly useful for tunnel junctions and memory. A new era doesn't mean replacing silicon overnight; it means a new device paradigm entering the toolbox. The early lab evidence and theory justify serious investment, and the burden is now on scaling, not skepticism.

Imagine a memory cell that switches spins fast like an antiferromagnet but reads like a ferromagnet, with no stray fields disturbing neighbors. That's the concrete target: the magnetic tunnel junction in MRAM. My opponent is right that fabs need cost, speed, and energy numbers at scale. But that's the normal path for any new device, and peer-reviewed transport and theory work already shows the mechanism is real. The question isn't whether altermagnets replace silicon tomorrow, but whether they earn a place in the toolbox. Demanding a full manufacturable chip before investing is backwards.

I'll concede the word "era" is doing work, but that's a definitional dodge. Electronics eras start when a material enables a device class old options can't match. Altermagnets' peer-reviewed spin-split bands with zero net magnetization enable field-free switching in an MTJ, which is exactly the MRAM bottleneck. The falsifiable metric is simple: field-free switching at CMOS-compatible current, energy per bit below STT-MRAM, and wafer-scale reproducibility. If those fail, I'll drop the claim. But demanding fab adoption before that data exists gets the burden backwards. The other side's caution is fair; it isn't a reason not to invest.