Fig. 2.

Differential ($V_B-V_A$) noise power spectrum of RED227 with $V_{\mathit{ds}}$ = 100 mV and $I_{\mathit{ds}}$ = 300 $\mathrm{\mu }$A and the mixing chamber at 17 mK. The black, grey and red solid lines show the decorrelated and raw data, and our noise model considering a parasitic capacitance of 20 pF, respectively. The total contributions from the two ionization channels A and B of the current ($I_n$), voltage ($E_n$), and Johnson noise sources are also shown as dashed purple, orange, and green lines, respectively