Rationale for femtosecond magnetism explored with x-ray core-hole excitation

摘要: In magnetic metals the core-hole excitation by x rays leads to a sudden creation of an impurity that is screened in spin-dependent way. A scattering experiment ${L}_{3}$ region terminating with $3s$ hole has already been shown give information on time scale this screening process. Here we present linear-rate model for analysis such experiments and apply Ni, Co, Fe metals. This yields quantitative results could not be obtained before using empirical model. The constant Ni (most likely $\ensuremath{\sim}1.5\text{ }\text{fs}$) definitely longer than Fe, which presumably caused narrow-band effects. 0.43 fs while 0.18 upper limit metal. agreement experiment, clarifies variation dichroism due competition between decay it takes accumulate charge. Finally, perspectives approach are briefly discussed including importance future diluted impurities.