Capacitors are known to add distortion to signals that pass through them, especially those that use a high-k dielectric such as the ceramic type. It's why capac

Capacitors are known to add distortion to signals that pass through them, especially those that use a high-k dielectric such as the ceramic type. It's why capacitor selection in ultra low distortion audio amplifiers is an important consideration. Leaving capacitive effects aside and concentrating on secondary effects, it's been my understanding until now the electric field in a bulk dielectric is never 100% in sync with the applied signal as the field itself physically distorts the dielectric, as such nonlineararities are introduced into the signal as it's transferred across the capacitor and that they vary to some degree with the signal's (field's) frequency and amplitude. Nevertheless, it's never been very clear to me what happens at the molecular level that contributes to this nonlineararity. Essentially, losses in capacitors are due to I²R in its electrodes, bulk resistive leakage within the dielectric as well as resistive impurities in the dielectric and that signal distortion is principally due to the intrinsic nature of the dielectric itself. That is, signal distortion is caused by the action of the field on the dielectric which physically distorts it, and although this action is essentially elastic the effective energy through the capacitor is never a 100% truly accurate analog of the applied signal in that group delay and related effects are introduced, and these contribute distortion (that is, energy essentially remains the same but the signal is changed albeit to a minuscule extent). This new work seems to indicate there are additional reasons for why capacitors contribute distortion to signals. After reading this article it's occurred to me to question how much heat is actually generated within the dielectric by, say, nonelastic strain or deformation of its crystal structure (through molecular movement, phonon coupling losses and or whatever). Heat generated through actual dielectric deformation is energy and by conservation of energy it has to come from the input signal. Signal distortion will then occur by virtue of some energy changing into heat which then becomes subject to thermal inertia. In effect, energy through the capacitor can be lost and if reabsorbed [by adiabatic process?] into the dielectric’s field then the transferred signal will not precisely mirror the input, thus additional distortion is incurred. Moreover, I'd then contend that distortion harmonics introduced into the signal by the dielectric and its related processes are not only likely to be complex but also frequency and amplitude dependent, and would only be predictable with a full understanding of both the dielectric's electrical properties and the heat flow within and around the dielectric. This mechanism may also account for why high-k ceramic capacitors are more lossy at higher frequencies (it also seems the only true distortionless capacitor would be the vacuum type where ε₀ is the effective 'dielectric'). I'd appreciate it if someone with a better understanding of these issues could enlighten me.