Quantum 1/f and classical phase noise in resonant bio-chemical MEMS sensors

While classical physics provides no universal 1/f spectrum, quantum mechanics and electrodynamics require the presence of fundamental quantum fluctuations of physical currents, cross sections, and process rates, because of the infrared quasi-divergence and radiative corrections. The present paper calculates these quantum fluctuations, shows that they have a simple universal 1/f spectrum, and shows how they invariably come to the foreground, being dominant at low frequencies in high-technology applications. This happens because in them all other fluctuations and sources of instability have been either eliminated, or otherwise discounted and put under control. BAW SAW and MEMS resonators are no exception. This defines detection limits and optimization rules for biological and chemical sensors based on them