Electronic refrigeration at the quantum limit.
We demonstrate quantum-limited electronic refrigeration of a metallic island in a low-temperature microcircuit. We show that matching the impedance of the circuit enables refrigeration at a distance, of about 50 microm in our case, through superconducting leads with a cooling power determined by the quantum of thermal conductance. In a reference sample with a mismatched circuit this effect is absent. Our results are consistent with the concept of electromagnetic heat transport. We observe and analyze the crossover between electromagnetic and quasiparticle heat flux in a superconductor.
Timofeev
Andrey V
AV
Low Temperature Laboratory, Helsinki University of Technology, 02015 TKK, Finland.
Helle
Meri
M
Meschke
Matthias
M
Möttönen
Mikko
M
Pekola
Jukka P
JP