SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Berakdar J.) "

Sökning: WFRF:(Berakdar J.)

  • Resultat 1-2 av 2
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Gray, A. X., et al. (författare)
  • Ultrafast terahertz field control of electronic and structural interactions in vanadium dioxide
  • 2018
  • Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 98:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Vanadium dioxide (VO2), an archetypal correlated-electron material, undergoes an insulator-metal transition near room temperature that exhibits electron-correlation-driven and structurally driven physics. Using ultrafast temperature- and fluence-dependent optical spectroscopy and x-ray scattering, we show that multiple interrelated electronic and structural processes in the nonequilibrium dynamics in VO2 can be disentangled in the time domain. Specifically, following intense subpicosecond terahertz (THz) electric-field excitation, a partial collapse of the insulating gap occurs within the first picosecond. At temperatures sufficiently close to the transition temperature and for THz peak fields above a threshold of approximately 1 MV/cm, this electronic reconfiguration initiates a change in lattice symmetry taking place on a slower timescale. We identify the kinetic energy increase of electrons tunneling in the strong electric field as the driving force, illustrating a promising method to control electronic and structural interactions in correlated materials on an ultrafast timescale.
  •  
2.
  • Perosa, G., et al. (författare)
  • Femtosecond Polarization Shaping of Free-Electron Laser Pulses
  • 2023
  • Ingår i: Physical Review Letters. - 0031-9007. ; 131:4
  • Tidskriftsartikel (refereegranskat)abstract
    • We demonstrate the generation of extreme-ultraviolet (XUV) free-electron laser (FEL) pulses with timedependent polarization. To achieve polarization modulation on a femtosecond timescale, we combine two mutually delayed counterrotating circularly polarized subpulses from two cross-polarized undulators. The polarization profile of the pulses is probed by angle-resolved photoemission and above-threshold ionization of helium; the results agree with solutions of the time-dependent Schrodinger equation. The stability limit of the scheme is mainly set by electron-beam energy fluctuations, however, at a level that will not compromise experiments in the XUV. Our results demonstrate the potential to improve the resolution and element selectivity of methods based on polarization shaping and may lead to the development of new coherent control schemes for probing and manipulating core electrons in matter.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-2 av 2

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy