These are between micrometer and millimeter sized, depending on technology and exactly what you count. But miniaturizing them is by far not the most pressing pr

These are between micrometer and millimeter sized, depending on technology and exactly what you count. But miniaturizing them is by far not the most pressing problem. And it will not be a server rack for now, rather a helium dilution refrigerator that works at less than 1 Kelvin.