Picosecond acoustics


Picosecond acoustics of phase transitions

When material undergoes a phase transition, its electronic, lattice, and magnetic structure may change. Such transitions can be triggered at a subpicosecond time scale by laser pulses. If the transition is accompanied by a lattice change, the atoms ‘click’ from one structure to the other, and this ‘click’ manifests itself as a picosecond strain pulse, which carry information about the intrinsic properties of the transition. With picosecond acoustics, we can ‘hear’ how various external stimuli affect internal dynamics during the ultrafast phase transitions. On the other hand, if we create a short strain pulse elsewhere, we can use it to ‘kick’ the lattice during the unstable period of ultrafast phase transition, affecting ultrafast processes during transition and, possibly, the final phase of the material.


Researchers involved in the projects

Alexandra Kalashnikova

Iaroslav Mogunov

Anatolii Fedianin


Recent publications

Ia. A. Mogunov, S. Lysenko, A. E. Fedianin, F. E. Fernández, A. Rúa, A. J. Kent, A. V. Akimov, A. M. Kalashnikova, Large non-thermal contribution to picosecond strain pulse generation using the photo-induced phase transition in VO2Nature Communications 11, 1690 (2020).


Ia. A. Mogunov, F. Fernández, S. Lysenko, A.J. Kent, A.V. Scherbakov, A.M. Kalashnikova, and A.V. Akimov, 

Ultrafast Insulator-Metal Transition in VO2 Nanostructures Assisted by Picosecond Strain PulsesPhys. Rev. Applied 11, 014054 (2019).


Ia. A. Mogunov, S. Lysenko, F. Fernández, A. Rúa, A. V. Muratov, A. J. Kent, A. M. Kalashnikova, and A. V. Akimov
Photoelasticity of VO2 nanolayers in insulating and metallic phases studied by picosecond ultrasonicsPhys. Rev. Materials 4, 125201 (2020).


Ia. A. Mogunov, S. Lysenko, A. E. Fedianin, A. J. Kent, A. V. Akimov, A. M. Kalashnikova, A role of a picosecond strain in an ultrafast optically-driven phase transition in VO2 nanostructures, Journal of Physics: Conference Series , 1461, 012108 (2020).