Ground-state cooling of a trapped ion using long-wavelength radiation

TL;DR

This paper demonstrates the use of radio-frequency radiation for ground-state cooling of a trapped ion, enabling efficient quantum state manipulation and significantly reducing motional heating rates.

Contribution

It introduces RF-based ground-state cooling of trapped ions and showcases motional state engineering with improved heating rate measurements.

Findings

Achieved a mean phonon number of 0.13 after sideband cooling.

Demonstrated Rabi oscillations between Fock states n=0 and n=1.

Reduced motional heating rate by nearly two orders of magnitude.

Abstract

We demonstrate ground-state cooling of a trapped ion using radio-frequency (RF) radiation. This is a powerful tool for the implementation of quantum operations, where RF or microwave radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of $\overline{n} = 0.13(4)$ after sideband cooling, corresponding to a ground-state occupation probability of 88(7)\%. After preparing in the vibrational ground state, we demonstrate motional state engineering by driving Rabi oscillations between the n=0 and n=1 Fock states. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost two orders of magnitude compared to our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system.