Nanoscale depth-resolved coherent femtosecond motion in laser-excited bismuth.
We employ grazing-incidence femtosecond x-ray diffraction to characterize the coherent, femtosecond laser-induced lattice motion of a bismuth crystal as a function of depth from the surface with a temporal resolution of 193+/-8 fs. The data show direct consequences on the lattice motion from carrier diffusion and electron-hole interaction, allowing us to estimate an effective diffusion rate of D=2.3+/-0.3 cm(2)/s for the highly excited carriers and an electron-hole interaction time of 260+/-20 fs.
Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. Steve.Johnson@mailaps.org
S L
SL
Johnson
P
P
Beaud
C J
CJ
Milne
F S
FS
Krasniqi
E S
ES
Zijlstra
M E
ME
Garcia
M
M
Kaiser
D
D
Grolimund
R
R
Abela
G
G
Ingold