A microwave frequency standard based on the laser cooled 113Cd+ ions

Trapped ions are applied to the precision frequency metrology thanks to the long interaction time between ions and radiation field. In the past decades, many groups in the world have built microwave or optical frequency standards based on different trapped ions and achieved great improvements. In this article, a microwave frequency standard developed at JMI is reported, which is based on the laser cooled ¹¹³Cd⁺ ions.