Fig. 2
From: Strong negative nonlinear friction from induced two-phonon processes in vibrational systems
Positive and negative nonlinear friction on the plate mode due to two-phonon processes. a Measured (dots) and calculated (lines) ringdown of the dimensional vibration amplitude A1 of mode 1 with no sideband pumping (black) and pumping at the red-/blue-detuned secondary sideband (red/blue) that leads to positive/negative nonlinear friction; Δ = −35 Hz. b The instantaneous decay rate as a function of the squared vibration amplitude. Dashed lines are from Eq. (6), solid lines show the extended adiabatic theory (Supplementary Note 2). c, d Similar plots as (a) and (b), for larger initial vibration amplitude. Error bars represent ±1 s.e.
