2003/12/31 by J. P. Pekola, Tero T. Heikkilä, T. T. Heikkila +7 · 3 citations
Physics and Astronomy · #Atomic physics #Condensed matter physics #Electron #Electron cooling #Limiting #Materials science #Metal #Nuclear physics #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum tunnelling #Relaxation (psychology) #Superconducting and THz Device Technology #Superconductivity #Thermal conduction #Thermodynamics #Yield (engineering) #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.92.056804
published as Phys. Rev. Lett. 92, 056804 (2004) · 4 pages, 4 figures, added Ref. [6] + minor corrections
openalex publication_date 2004/02/06 · arxiv created 2004/02/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We demonstrate both theoretically and experimentally two limiting factors in cooling electrons using biased tunnel junctions to extract heat from a normal metal into a superconductor. First, when the injection rate of electrons exceeds the internal relaxation rate in the metal to be cooled, the electrons do not obey the Fermi-Dirac distribution, and the concept of temperature cannot be applied as such. Second, at low bath temperatures, states within the gap induce anomalous heating and yield a theoretical limit of the achievable minimum temperature.