We have incorporated an aluminum single electron transistor (SET) directly ontop of a vertical quantum dot, enabling the use of the SET as an electrometerthat is extremely responsive to the motion of charge into and out of the dot.Charge induced on the SET central island from single electron additions to thedot modulates the SET output, and we describe two methods for demodulation thatpermit quantitative extraction of the quantum dot capacitance signal. The twomethods produce closely similar results for the determined single electroncapacitance peaks.
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