Dark state cooling of a trapped ion using microwave coupling

TL;DR

This paper introduces a microwave-based dark-state cooling method for trapped ions that effectively reduces motional energy below recoil limits, offering robustness and scalability for ion chip applications.

Contribution

The authors develop a novel dark-state cooling scheme using microwave dressing to achieve efficient, broad-band cooling of trapped ions, especially suitable for large-scale ion chips.

Findings

Cooling below recoil limit achieved

Robustness to microwave and laser fluctuations demonstrated

Suitable for large-scale ion chip implementations

Abstract

We propose a new dark-state cooling method of trapped ion systems in the Lamb-Dicke limit. With application of microwave dressing the ion, we can obtain two electromagnetically induced transparency structures. The heating effects caused by the carrier and the blue sideband transition vanish due to the EIT effects and the final mean phonon numbers can be much less than the recoil limit. Our scheme is robust to fluctuations of microwave power and laser intensities which provides a broad cooling bandwidth to cool motional modes of a linear ion chain. Moreover, it is more suitable to cool four-level ions on a large-scale ion chip.