Ultrafast demagnetization in the sp-d model: a theoretical study

Details Ultrafast demagnetization in the sp-d model: a theoretical study Ultrafast demagnetization in the sp-d model: a theoretical study

2007-03-02

arxiv.org/abs/cond-mat/0703049v2

Phys. Rev. B 76, 045205 (2007)

Physics

Condensed Matter

Mesoscale and Nanoscale Physics

15 pages, 8 figures

Scientific paper

10.1103/PhysRevB.76.045205

We propose and analyze a theoretical model of ultrafast light-induced magnetization dynamics in systems of localized spins that are coupled to carriers' spins by sp-d exchange interaction. A prominent example of a class of materials falling into this category are ferromagnetic (III,Mn)V semiconductors, in which ultrafast demagnetization has been recently observed. In the proposed model light excitation heats up the population of carriers, taking it out of equilibrium with the localized spins. This triggers the process of energy and angular momentum exchange between the two spin systems, which lasts for the duration of the energy relaxation of the carriers. We derive the Master equation for the density matrix of a localized spin interacting with the hot carriers and couple it with a phenomenological treatment of the carrier dynamics. We develop a general theory within the sp-d model and we apply it to the ferromagnetic semiconductors, taking into account the valence band structure of these materials. We show that the fast spin relaxation of the carriers can sustain the flow of polarization between the localized and itinerant spins leading to significant demagnetization of the localized spin system, observed in (III,Mn)V materials.

Affiliated with

Also associated with

No associations

Rating

Ultrafast demagnetization in the sp-d model: a theoretical study does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Ultrafast demagnetization in the sp-d model: a theoretical study, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ultrafast demagnetization in the sp-d model: a theoretical study will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-284311