  We report here on a direct and non-invasive measurement of the charge and its
distribution in a Kondo correlated quantum dot (QD). A non-invasive
potential-sensitive detector in proximity with the QD reveals that even though
the conductance of the QD is significantly enhanced as it enters the Kondo
regime the net charge in the QD remains unaffected. This demonstrates the
separation between spin and charge degrees of freedom in the Kondo effect. We
find however, under certain experimental conditions, that an abrupt
redistribution of the charge in the QD is taking place simultaneously with the
onset of Kondo correlation. This suggests that the spin-charge separation in
the Kondo effect does not always hold.
