  We predict ultrafast modulation of the pure molten metal surface stress
fields under the irradiation of the single femtosecond laser pulse through the
two-temperature model molecular-dynamics simulations. High-resolution and
precision calculations are used to resolve the ultrafast laser-induced
anisotropic relaxations of the pressure components on the time-scale comparable
to the intrinsic liquid density relaxation time. The magnitudes of the dynamic
surface tensions are found being modulated sharply within picoseconds after the
irradiation, due to the development of the nanometer scale non-hydrostatic
regime behind the exterior atomic layer of the liquid surfaces. The reported
novel regulation mechanism of the liquid surface stress field and the dynamic
surface tension hints at levitating the manipulation of liquid surfaces, such
as ultrafast steering the surface directional transport and patterning.
