ABSTRACT
Tunnel junction refrigeration was ›rst realized in the 1990s (Nahum et al. 1994, Leivo et al. 1996) and uses an energy-selective tunnel barrier to extract hot electrons. še cooling power of these tunnel junctions is typically quite low, in the order of pW; however, if the volume to be cooled is small and the heat load (mainly from the lattice) is su´ciently low (which occurs at sub-Kelvin temperatures), these tunnel junctions are able to cool electrons from an initial bath temperature of around 300 mK to 100 mK and below.
