arXiv subjects

Alexej Pashkin

Publications and source records attributed to Alexej Pashkin.

20 records · Page 2Linked to original sources

arXiv2017

Ultrafast Carrier Dynamics in VO$_2$ across the Pressure-Induced Insulator-to-Metal Transition

We utilize near-infrared pump and mid-infrared probe spectroscopy to investigate the ultrafast electronic response of pressurized VO$_2$. Distinct pump-probe signals and a pumping threshold behavior are observed even in the pressure-induced metallic state showing a noticeable amount of localized electronic states. Our results are consistent with a scenario of a bandwidth-controlled Mott-Hubbard transition.

cond-mat.str-el↗

arXiv2015

Controlled Polar Asymmetry of Few-Cycle and Intense Mid-Infrared Pulses

We demonstrate synthesis of super-octave-spanning and phase-locked transients in the multi-terahertz frequency range with amplitudes exceeding 13 MV/cm. Sub-cycle polar asymmetry of the electric field is adjusted by changing the relative phase between superposed fundamental and second harmonic components. The resultant broken symmetry of the field profile is directly resolved via ultrabroadband electro-optic sampling. Access to such waveforms provides a direct route for control of low-energy degrees of freedom in condensed matter as well as non-perturbative light-matter interactions.

physics.optics↗