OBSERVATION OF COULOMB-BLOCKADE OSCILLATIONS IN THE THERMOPOWER OF A QUANTUM-DOT

We employ thermoelectric measurements on a quantum dot in order to obt ain new insights into the Coulomb blockade of single electron tunnelin g. For applied temperature differences of below 2 K, as the dot is dep leted by a surface gate, the thermopower oscillates about zero with a period corresponding to the removal of a single electron. The results are in reasonable agreement with a linear response expression for ther mopower which assumes metallic conduction.