Magneto-optical memory stores bits in the magnetisation of a material and writes or reads them with light on a photonic chip; cell-level demonstrations and wafer-scale garnet films on silicon now exist, but nothing resembling an addressable array does.
Summary
Magneto-optical (MO) memory combines two mature ideas. The storage element is magnetic and therefore non-volatile: a magnetic tunnel junction, a ferrimagnetic garnet film, or a two-dimensional magnet. The access mechanism is optical: light either flips the magnetisation directly (all-optical switching, typically with femtosecond pulses) or senses it through the Faraday and Kerr effects, in which magnetisation rotates the polarisation of transmitted or reflected light. Put on a photonic integrated circuit, the appeal is that a photonic processor could keep its weights or state in place without converting to the electrical domain to read or write them.
Evidence base
Open questions
Assessment drafted 2026-08-31 from up to 11 KB sources using the technology-scorecard framework; scores are a draft read pending review.