a) b) c) Gate Voltage (V) I -40 -20 0 20 40 33 31 29 27 F re quency (MHz) F re quency (MHz) -40 -20 0 20 40 39 37 35 Gate Voltage (V) Gate Voltage (V) 29 MHz (nA)) I mix Log 10 ( -1.0 -0.5 0.0 40 20 0 -20 -40 Frequency (MHz) Gate Voltage (V) 32.0 31.5 31.0 -40 -20 0 20 40 d) 300 200 100 Q 55 50 45 40 35 Absolute Gate Voltage (V) For +ve V g For -ve V g For +ve V g For -ve V g 12 8 4 0 Amplitude (nm)  50 45 40 35 Absolute Gate Voltage (V) 55 e) f) FIG. 2: (color online) a) and b) Color logscale plots of mixing current as a function of V DC g and ω/ 2 π for two devices (for device-1, Fig.2a, diameter d=100 nm, length l=2.9 µ m, for device-2, Fig.2b, d=120 nm, l= 3.1 µ m). c) Calculated dispersion as a function of V DC g . d) Lineplot at 29 MHz for device-1 (dashed line in Fig.2a). e) The plot of the Q as a function of V DC g for device-1. f) The plot of the “amplitude” z reso amp as a function of V DC g for device-1. (The red and blue traces in Fig.2e, and in Fig.2f, show the data for negative and positive gate voltages). 13