Atomic-scale time and space resolution of terahertz frequency acoustic waves.
Using molecular dynamics simulations and analytics, we find that strain waves of terahertz frequencies can coherently generate radiation when they propagate past an interface between materials with different piezoelectric coefficients. By considering AlN/GaN heterostructures, we show that the radiation is of detectable amplitude and contains sufficient information to determine the time dependence of the strain wave with potentially subpicosecond, nearly atomic time and space resolution. We demonstrate this phenomenon within the context of high amplitude terahertz frequency strain waves that spontaneously form at the front of shock waves in GaN crystals.
Reed
Evan J
EJ
Chemistry, Materials, and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94551, USA. reed23@llnl.gov
Armstrong
Michael R
MR
Kim
Ki-Yong
KY
Glownia
James H
JH