51st Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 65, Number 4
Monday–Friday, June 1–5, 2020;
Portland, Oregon
Session N05: FOCUS: Ultrafast Processes in Solids
10:30 AM–12:30 PM,
Thursday, June 4, 2020
Room: D139-140
Co-Sponsoring
Unit:
DCMP
Chair: Alexandra Landsman, Ohio State University
Abstract: N05.00001 : \textbf{Using light to control electrons to create new light}.
10:30 AM–11:00 AM
Live
Preview Abstract
Abstract
Author:
Paul Corkum
(University of Ottawa)
Intense Gaussian light can create an electron-hole pair in a semiconductor
(or dielectric) and guide the relative electron-hole trajectory. Before
dephasing, in semiconductors (and some dielectrics), the electron and hole
have a significant chance of re-encountering each other where they can
re-combine, creating a sub-cycle optical burst of coherent, short-wavelength
radiation. Repeated over many cycles, we produce high harmonic radiation
stretching into the VUV.
We use in-situ measurement to confirm that the process I have just described
is valid (and very similar to what occurs in gases). One notable distinction
is that the absorption length of VUV light in solids is very short, thereby
weakening the influence of phase matching. However, I will show that phase
matching still plays a role [1].
What I have described above happens locally, everywhere across the beam
profile, but by using vector beams, light control over electrons and holes
can also be at the whole beam level, especially when combined with coherent
control (using a beam and its second harmonic). I will show that we can
drive directed currents even with relatively low intensity light.
Surprisingly, all we need is two pathway interference to drive currents with
360 degree control pixel-by-pixel with only the relative phase between a
circularly polarized beam and linear polarized second harmonic as a
variable.
One important application is to generate THz solenoidal magnetic field
transients. I will show that we create ring currents in GaAs with an
associated magnetic field [2]. We predict very large ring currents and very
large magnetic field transients in breakdown gases [3].
[1] A. Korobenko, et al., \textit{Opt Express}. \textbf{27}, 32630 (2019).
[2] S. Sederberg, F. Kong, F. Hufnagel, E. Karimi, C. Zhang, P. B. Corkum,
unpublished results.
[3] S. Sederberg, F. Kong, P. B. Corkum,$^{\mathrm{\thinspace }}$unpublished
results.