Time-dependent density functional theory (TDDFT) is a first principles, quantum mechanical, method for simulating the dynamics of many-electron systems under the influence of external perturbations, e.g. laser pulses. It is most commonly used in the linear regime, where it may be used to calculate the optical absorption spectrum of atoms,molecules,clusters, and solids. However, in recent years, it has been applied to study real-time laser-induced dynamics, and in particular, ultrafast spin dynamics in condensed matter systems .In this talk I will first broadly discuss the TDDFT method before focusing on some of our recent results including the prediction and observation of OISTR (optical inter-sublattice spin transfer) [2,3] and how TDDFT may be extended to calculate transient XMCD signals .
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