Theory 05/Ultrafast/Magnetism
Demagnetisation Is Spin Against Lattice
The claim
Ultrafast demagnetisation rate is set by the ratio of spin-lattice relaxation time to pulse duration, not by pulse energy.
01Mechanism
The pulse heats electrons, and spins equilibrate with the lattice on a characteristic time; the ratio determines how much order is lost.
02Prediction
Rate should track the ratio.
03Refutation
Rate tracking fluence would remove relaxation.