Laboratory of Spin Physics of two-dimensional Materials

One of the results of the action of a focused femtosecond laser pulse on a substance is the excitation of local mechanical stresses, which subsequently propagate in various directions in the form of sound waves. The capabilities of the optical pump-probe technique make it possible to excite and study these waves, usually having frequencies of tens and hundreds of gigahertz, which opens up wide opportunities for sensing, materials processing, and fundamentally new fundamental research. This scientific direction is called picoacoustics. In our Lab we study propagation of surface acoustic waves and longitudinal waves through flakes of 2D materials and semiconducting heterostructures, combine optical pump-probe with microscopy and study the influence of the acoustical wave on nonlinear properties of the materials.

Description

Conductivity is a sensitive characteristic in relation to many physical phenomena, but its experimental measurement usually takes quite a long time - from microseconds. At the same time, the laser pulse can lead to a change in the state of the electronic system, causing a phase transition, heating or activation of photoexcited carriers. The possibility of studying the kinetics of relaxation of photoconductivity by the pump-sensing method implemented in our laboratory makes it possible to study a wide range of phenomena in which relaxation in the nanosecond region is essential.

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