  The exploration of the rich dynamics of electrons is a frontier in
fundamental nano-physics. The dynamical behavior of electrons is dominated by
random and chaotic thermal motion with ultrafast ($\approx$ ps) and nanoscale
scatterings. This generates fluctuating electromagnetic fields in close
vicinity of the moving electrons. W studied this fluctuation in small
structures and found that its spatial distribution is not uniform, the
magnitude of the fluctuation depends on external parameters such as the size (
~1 $\mu m$) and the shape of the structure and changes can occur by an order of
magnitude. Our work opens the possibility of improving the signal to noise
ratio in small devices and in manipulating microscopic electron kinematics
through nano-optical techniques and to applications in thermal detectors and
photothermal photovoltaics.
