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IMM colloquium by prof. Alexey Kimel (Spectroscopy of Solids and Interfaces) (Lecture)

Date
Tuesday 27 June 2017Add to my calendar
Time
from 16:00
Location
HG00.307
Speaker
prof. Alexey Kimel (SSI)
Description


Kimel AV-DvA-156654Controlling the magnetic state of media with the lowest possible cost of energy and simultaneously at the fastest possible time-scale is a new and great challenge in fundamental magnetism. At the same time this is becoming an increasingly urgent issue in technology, where data centers already consume 5% of the world electricity production.
A femtosecond laser pulse excites magnets much faster than characteristic times of atomic, orbital and spin motion and steers magnetization dynamics along yet unexplored, non-thermodynamic routes. One of these routes was discovered by our group showing that a femtosecond laser pulse could facilitate the fastest ever write-read magnetic recording event, accompanied by a record low, but still substantial, dissipation. Inspired by these opportunities we try to challenge the borders of femtosecond opto-magnetism and to achieve the fastest, least dissipative switching of the order parameters in magnets. For this purpose, we employ the strongest interactions in magnetism – the spin-orbit interaction and the exchange coupling between spins. The idea is to achieve ultrafast changes in the magnetic order so that the entropy of the medium does not have time to increase and consequently the heat load vanishes. In my talk I would like to review recent progress in our search for the ways allowing ultrafast and cold opto-magnetic recording [1-7]. I will also discuss ideas for new experiments  with high magnetic fields, the strength of which is getting comparable to that of the spin-orbit and the exchange interactions, and electromagnetic radiation in a broad spectral range including infrared photons with energies at the scale of the exchange energy.