New record in nanoelectronics at ultralow temperatures

The first ever measurement of the temperature of electrons in a nanoelectronic device a few thousandths of a degree above absolute zero was demonstrated in a joint research project performed by Lancaster University, VTT Technical Research Centre of Finland Ltd, and Aivon Ltd. The team managed to make the electrons in a circuit on a silicon chip colder than had previously been achieved. Dr Rich Haley, Head of Ultra Low Temperature Physics at Lancaster, said: "This is a notable achievement in that the team has finally broken through the 4 millikelvin barrier, which has been the record in such structures for over 15 years." Although it has long been possible to cool samples of bulk metals even below 1 millikelvin, it has proved very difficult to transfer this temperature to electrons in small electronic devices, mainly because the interaction between the conducting electrons and the crystal lattice becomes extremely weak at low temperatures. By combining state-of-the-art micro and nanofabrication and pioneering measurement approaches the research team realized ultralow electron temperatures reaching 3.7 millikelvin in a nanoelectronic electron tunnelling device. A scientific article on the subject has been published in Nature. This breakthrough paves the way towards sub-millikelvin nanoelectronic circuits and is another step on the way to develop new quantum technologies including quantum computers and sensors. Quantum technologies use quantum mechanical effects to outperform any possible technology based only on classical physics.