Quick search Find article
Quick search
Find article

Delay of laser excited electron/hole interaction with germanium lattice

Edward A Stern1 and Dale Brewe2

Show affiliations


Laser pump/XAFS probe study of Ge using the high efficiency facility at PNC/XOR CAT at sector 20 of the Advanced Photon Source (APS) has discovered some surprising results of how the excited electrons/hole (e/h) decay. The 200 femtosecond (fs) pulse laser is triggered at the frequency of the APS ring so as to use the x-rays of one pulse of the 24 singlet mode at 100% efficiency. The higher efficiency of the use of the ring's x-rays (about two orders more efficient than usual) allowed the measurement of XAFS spectra at a large number of delay times between laser pump and x-ray probe and at different laser powers. The XAFS data determined the time dependence of the relative distances and their vibration amplitudes of the first and second Ge neighbors. The laser pulse excites a classical long wavelength optical mode that within 0.1 picoseconds (ps) or so excites only the vibrations of the 1st neighbor while to excite the second neighbor requires decay of the excited e/h through coupling with incoherent phonons. The surprising result is that this decay is delayed 11 ps, independent of the laser power as it is increased by a factor of two.


PACS

63.20.K- Phonon interactions

78.70.Dm X-ray absorption spectra

78.47.-p Spectroscopy of solid state dynamics

72.40.+w Photoconduction and photovoltaic effects

Subjects

Condensed matter: electrical, magnetic and optical

Condensed matter: structural, mechanical & thermal

Dates

Issue 1 (2009)



  1. Delay of laser excited electron/hole interaction with germanium lattice

    Edward A Stern and Dale Brewe 2009 J. Phys.: Conf. Ser. 190 012053

  2. Current redistribution of a current carrying superconducting tape in a perpendicular magnetic field

    J Yoo et al 2009 Supercond. Sci. Technol. 22 125019

  3. A novel symmetrical microwave power sensor based on GaAs monolithic microwave integrated circuit technology

    De-bo Wang and Xiao-ping Liao 2009 J. Micromech. Microeng. 19 125012

  4. Investigation of pellet-driven magnetic perturbations in different tokamak scenarios

    T Szepesi et al 2009 Plasma Phys. Control. Fusion 51 125002

  5. Improvements in modeling EXAFS with many-pole self-energy and FEFF 8.5

    Matthew Newville et al 2009 J. Phys.: Conf. Ser. 190 012023

  6. Progress in applications of magnetic nanoparticles in biomedicine

    Kevin O'Grady 2009 J. Phys. D: Appl. Phys. 42 220301

  7. pH sensitive CdS–iron oxide fluorescent–magnetic nanocomposites

    Dhananjay Thakur et al 2009 Nanotechnology 20 485601

  8. Identification of a time-varying point source in a system of two coupled linear diffusion-advection- reaction equations: application to surface water pollution

    Adel Hamdi 2009 Inverse Problems 25 115009

  9. Stable centred tetragonal phases in the hard core Yukawa system

    Gernot J Pauschenwein and Gerhard Kahl 2009 J. Phys.: Condens. Matter 21 474202

  10. Melting tungsten nanoparticles: a molecular dynamics study

    Amitava Moitra et al 2008 J. Phys. D: Appl. Phys. 41 185406

Related review articles

What's this?
View review articles related to this research to gain an insight into the key trends in this subject area. Related review articles are selected based on PACS/MSC codes, and are no more than three years old.

  1. Dynamic model of supersonic martensitic crystal growth
  2. Dynamics of nuclear wave packets at the F center in alkali halides
  3. Interaction of coherent phonons with defects and elementary excitations
More

View by subject




Export






Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.