Phonon-Laser Ultrasensitive Force Sensor

Developing nanomechanical oscillators for ultrasensitive force detection is very useful in exploring science. We report our achievement of the external regarding radiofrequency electric field by a nanosensor made single trapped ${}^{40}{\mathrm{Ca}}^{+}$ ion under injection locking, where squeezing additionally applied to smallest trap. The employed confined stably surface electrode trap and works as phonon laser that sensitive disturbance. locking drove ion's oscillation with phase synchronization, yielding sensitivity 347 $\ifmmode\pm\else\textpm\fi{}50\phantom{\rule{0.2em}{0ex}}\mathrm{yN}/\sqrt{\mathrm{Hz}}$. Further 3-dB on variance, we achieve successful be $86.5\ifmmode\pm\else\textpm\fi{}70.1$ yN.