Ab initio study of ultrafast spin dynamics in Gdx(FeCo) 1−x alloys

  title={Ab initio study of ultrafast spin dynamics in Gdx(FeCo)
1−x alloys},
  author={J. K. Dewhurst and Sam Shallcross and Ilie Radu and Peter Elliott and C. v. Korff Schmising and S. Sharma},
  journal={Applied Physics Letters},
Using an ultrashort laser pulse we explore ab-initio the spin dynamics of Gdx(FeCo)1−x at femtosecond time scales. Optical excitations are found to drive charge from Fe majority d-states to the unoccupied Gd f -minority states, with f -electron character excited occupation lagging behind that of the d-electron character, leading to substantial demagnetisation of both species while leaving the global moment almost unchanged. For x > 0.33 this results in the creation of an ultrafast ferromagnetic… 

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