Cooling, conductance and thermometric performance of non-ideal normal metal-superconductor tunnel junction pairs

Abstract

We have investigated the effect of a difference in the tunnelling resistances of the individual normal metal-insulator-superconductor (NIS) tunnel junctions in a double junction SINIS device, with particular emphasis on the impact on the conductance, cooling and thermometric performance. By solving the electrical and thermal equations of the junctions in a self-consistent way, we find that asymmetry gives rise to many new features, such as appearance of an excess sub-gap current, improved cooling performance, exhibition of negative differential resistance, and improved temperature range of thermometric sensitivity. Experiments were also carried out to complement some of the numerical results. In addition, we studied theoretically and experimentally the effect of a finite series resistance, which also causes an excess current in the subgap region, and a suppression of the conductance maxima at the gap edge. Experimental results agree well with the theoretical predictions.

14 pages

References in corpus (11)

• Single-mode heat conduction by photons
• Photon assisted tunneling as an origin of the Dynes density of states
• Recombination limited energy relaxation in a BCS superconductor
• Non-adiabadic charge pumping in a hybrid SET transistor
• Phonon cooling of nanomechanical beams with tunnel junctions
• Electron and phonon Cooling in a Superconductor - Normal Metal - Superconductor Tunnel Junction
• Influence of Phonon dimensionality on Electron Energy Relaxation
• Thermal conductance of a proximity superconductor
• Electron energy relaxation by phonons in the Kondo condensate
• Insensitivity of sub-Kelvin electron-phonon coupling to substrate properties
• Effects of charging energy on SINIS tunnel junction thermometry

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• Sub-micron normal-metal/insulator/superconductor tunnel junction thermometer and cooler using Nb
• Existence of an Independent Phonon Bath in a Quantum Device
• Thermal conductance of Nb thin films at sub-kelvin temperatures
• Superconducting tunnel junction fabrication on three-dimensional topography via direct laser writing