The tricky bit isn't to get atoms to fuse. That's a fairly simple lab bench experiment. The problem is creating the right conditions where the fusion reaction is self-sustaining, with a net energy output. That means reaching temperatures of between 100 – 150 million °C (180 – 270 million °F), a pressure of five to 10 atmospheres at the point of reaction, and keeping a high-energy plasma stable for at least 10 seconds.
Nowhere in the article is said that they actually achieved these temperatures. This is poor journalism at its worst