We use specialised refrigeration technology called the dilution refrigerators to get to these ultra-low temperatures.
我们使用称为稀释冰箱的专业制冷技术来达到这些超低温。
英语百科
Dilution refrigerator
A He/He dilution refrigerator is a cryogenic device that provides continuous cooling to temperatures as low as 2mK, with no moving parts in the low-temperature region. The cooling power is provided by the heat of mixing of the Helium-3 and Helium-4 isotopes. It is the only continuous refrigeration method for reaching temperatures below 0.3K.