'Before the magnetic field is reduced, the heat generated by the magnetization needs to be absorbed by other means in order to obtain effective magnetic cooling. This is how we successfully cooled the nanoelectronic chip to 2.8 milliKelvin to achieve a record low temperature. Method. '
Professor Zumbühl and his colleagues combine these two cooling systems, both of which are based on magnetic cooling.
They cooled all the conductive connections of the chip to 150 micro Kelvin (less than one thousandth of a degree from absolute zero).
They then applied the second cooling system directly to the chip itself and placed a Coulomb blockage thermometer at the same time. The structure and material of the thermometer allowed it to be cooled down to 2.8 milliKelvins by magnetic cooling.
Prof. Zumbühl said: 'We combined two cooling systems to cool the chip below 3 milliKelvin (about 273.15 degrees Celsius). We are optimistic that we can use the same method to achieve 1 milliKelvin.'
The scientists said: 'We were able to keep the chips at ultra-low temperatures for 7 hours. This is quite good. Scientists will have plenty of time to conduct multiple exploration experiments, which will help to understand the physics characteristics near absolute zero.'
