Prospects for high-sensitivity continuous force detection with a single trapped ion

Dominika Durovcikova | Vivishek Sudhir

We propose and analyse in detail a new scheme for high-sensitivity continuous force detection using a single trapped ion transducer. Force detection is enabled through a continuous measurement of the ion’s displacement by coupling the motion of the trapped ion to a microwave cavity field via image currents induced by the charge in an antenna. The figure shows a schematic of this detector. We show that currents induced by the microwave cavity field allow high-precision displacement readout, and cause the charge’s motional frequency and damping rate to be modified depending on the detuning between the motional frequency and the microwave probe. Finally, we derive the quantum limits to the sensitivity with which the charge’s motion can be monitored. In particular we show that despite the disparity in size between that of a single ion and the wavelength of the microwave field, it is possible in principle to continuously monitor the charge’s zero-point motion.

Funding Sources: Research Assistantship | Teaching Assistantship (Spring 2022)