  We have developed a broadband scanning tunnelling microscope capable of
conventional, low frequency (<10 kHz), microscopy as well spectroscopy and
shot-noise detection at 1 MHz. After calibrating our AC circuit on a gold
surface, we illustrate our capability to detect shot-noise at the atomic scale
and at low currents (<1 nA) by simultaneously measuring the atomically resolved
differential conductance and shot-noise on the high temperature superconductor
Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+x}$. We further show our direct sensitivity to
the temperature of the tunnelling electrons at low voltages. Our broadband
probe opens up the possibility to study charge and correlation effects at the
atomic scale in all materials accessible to STM.

Mesoscale and Nanoscale Physics;Strongly Correlated Electrons