Scientists at the University of Basel have cooled a nanoelectronic chip to a temperature lower than 3 millikelvin. Cooling to this level will enable experiments that enhance the understanding of physics at close to absolute zero.
Physicists aim to cool their equipment to as close to absolute zero as possible, because these are the ideal conditions for quantum experiments, explains the University of Basel in a press release. Absolute zero is at 0 kelvin, or -273.15°C. The scientists from the Department of Physics and the Swiss Nanoscience Institute have set a record with their work and made the coldest chip in the world. The nanoelectronic chip was cooled to a temperature lower than 3 millikelvin.
The research group led by Basel physicist Professor Dominik Zumbühl applied a magnetic field to achieve the extreme cooling. Magnetic cooling involves the prevention of external heat flow and removing the heat that is generated by magnetisation. Christian Scheller and Mario Palma, the first authors of the study published in Applied Physics Letters, successfully used a combination of two cooling systems in their experiment: cooling the chip’s electrical connections and cooling the chip itself.
“The combination of cooling systems allowed us to cool our chip down to below 3 millikelvin, and we are optimistic than we can use the same method to reach the magic 1 millikelvin limit,” explains Zumbühl in the press release. Impressively, scientists were able to maintain this extremely low temperature of less than 3 millikelvin for a period of seven hours. This provides enough time to conduct various experiments that will help to understand the properties of physics close to absolute zero.