Condensed Matter Seminar
Friday 13 December 2019, 3:00pm to 4:00pm
Venue
Physics C36Open to
Alumni, Postgraduates, Staff, UndergraduatesRegistration
Registration not required - just turn upEvent Details
Light-driven ultrafast phonomagnetism
Over the past few decades, ultrashort pulses of light have been widely employed to control the behaviour of matter in its different phases. This is a particularly interesting challenge in magnetism, where the speed, dissipation and routes for ultimately fast switching of the spin orientation often lead to proposals for novel approaches in information processing and data recording.
In this work we control the magnetic state by resonantly pumping optical phonons, low-energy elementary vibrations of the crystalline lattice. We demonstrate that by exciting the crystal lattice of the prototypical antiferromagnetic DyFeO3, it can be driven within picoseconds into a transient metastable magnetic state. The state is characterized by a change in the strength of magnetic anisotropy along different crystal axes. This is experimentally seen as a long-lived shift in the frequency of the spin precession driven along the corresponding axes. For sufficiently strong excitation, this promotes an instability of the initial magnetic structure and launches a spin reorientation transition within a few picoseconds.
Speaker
Dr. Dmytro Afanasiev
Delft University of Technology
Contact Details
Name | Dr Sergey Kafanov |