«It's an enormous achievement that you can build optical clocks so good that you can now see relativity in the lab,» he says. (scientificamerican.com)
But the development of optical clocks based on aluminum ions, which can keep time to within one second in roughly 3.7 billion years, allows researchers to expose those diminutive relativistic effects. (scientificamerican.com)
Experimental realization, by using 9Be + as the logic ion and 27Al + as the spectroscopy ion, indicates the feasibility of applying this technique to make accurate optical clocks based on single ions. (science.sciencemag.org)