Cooling electrons from 1 K to 400 mK with V-based nanorefrigerators

摘要: The fabrication and operation of V-based superconducting nanorefrigerators is reported. Specifically, electrons in an Al island are cooled thanks to hot-quasiparticle extraction provided by tunnel-coupled V electrodes. Electronic temperature reduction down 400 mK starting from 1 K demonstrated with a cooling power ~20 pW at for junction area 0.3 micron^2. present architecture extends higher temperatures refrigeration based on tunneling between superconductors paves the way implementation multi-stage on-chip scheme operating above regime.