Re:Where does it say that they were able to READ? (Score 1)

Presumably using the Magento-Optic Kerr effect; light reflected from the surface of a magnetic material is circularly polarised. It sounds like they're recording using this effect in reverse, so read and write speed should be comparable.

However, TFA says 'managed to transfer data at intervals of about 40 femtoseconds' which is surely very misleading - it implies they wrote data at 25GHz. Given their spot size of 5um, that would require the medium to be moving at 125,000 m/s.

Of course, the actual paper says something quite different; their key achievement is being able to change the magnetisation of a domain in just 40 femtoseconds.