Ultra fast X-ray absorption spectroscopy of Ni during demagnetization

A German group at BESSY II recently succeeded in studying the evolution of both the spin (S) and orbital angular (L) momentum of a thin Ni film during ultrafast demagnetization, by means of X-ray magnetic circular dichroism (XMCD). It was found that both S and L components decrease by irradiating a femtosecond laser pulse, and the time constant is 130±40 fs. For more information, see the paper, "Femtosecond x-ray absorption spectroscopy of spin and orbital angular momentum in photoexcited Ni films during ultrafast demagnetization", C. Stamm et al., Phys. Rev, B81, 104425 (2010).