  Sensitive charge detection has enabled qubit readout in solid-state systems.
Recently, an alternative to the well-established charge detection via on-chip
electrometers has emerged, based on in situ gate detectors and radio-frequency
dispersive readout techniques. This approach promises to facilitate scalability
by removing the need for additional device components devoted to sensing. Here,
we perform gate-based dispersive readout of an accumulation-mode silicon
quantum dot. We observe that the response of an accumulation-mode gate detector
is significantly affected by its bias voltage, particularly if this exceeds the
threshold for electron accumulation. We discuss and explain these results in
light of the competing capacitive contributions to the dispersive response.
