A trapped-ion phonon laser and the detection of ultra-weak forces

This dissertation reports on the demonstration of a mechanical analogue to an optical laser, a ¿phonon laser¿, using a single trapped ion. Furthermore, we show that the dynamics of this system are surprisingly sensitive to external fields; we demonstrate phase synchronization (¿injection locking¿) to an external signal by applying forces as weak as 5 yN (yocto=10¿24). This enormous sensitivity might allow the detection of the nuclear spin of a single atom or molecule.