Related papers: Efficient electronic cooling above 2 K by niobium-…
We have successfully fabricated Cu/AlOx-Al/Nb normal-metal/insulator/superconductor tunnel junction devices with a high value of the superconducting gap (up to $\sim 1$ mV), using electron-beam lithography and angle evaporation techniques…
In electronic cooling with superconducting tunnel junctions, the cooling power is counterbalanced by the interaction with phonons and by the heat flow from the overheated leads. We study aluminium-based coolers that are equipped with a…
We have successfully fabricated micron-scale Cu-AlO$_{x} $-Al-NbN normal metal-insulator-superconductor (NIS) tunnel junction devices, using pulsed laser deposition (PLD) for NbN film growth, and electron-beam lithography and shadow…
Micro-refrigerators that operate in the sub-kelvin regime are a key device in quantum technology. A well-studied candidate, an electronic cooler using Normal metal - Insulator - Superconductor (NIS) tunnel junctions offers substantial…
We have developed a technique to fabricate sub-micron, 0.6 um x 0.6 um Al-AlOx-Nb tunnel junctions using a standard e-beam resist, angle evaporation and double oxidation of the tunneling barrier, resulting in high quality niobium, as…
When biased at a voltage just below a superconductor's energy gap, a tunnel junction between this superconductor and a normal metal cools the latter. While the study of such devices has long been focussed to structures of submicron size and…
The fabrication and operation of V-based superconducting nanorefrigerators is reported. Specifically, electrons in an Al island are cooled thanks to hot-quasiparticle extraction provided by tunnel-coupled V electrodes. Electronic…
Refrigeration is an important enabler for quantum technology. The very low energy of the fundamental excitations typically utilized in quantum technology devices and systems requires temperature well below 1 K. Expensive cryostats are…
We demonstrate an original method -- based on controlled oxidation -- to create high-quality tunnel junctions between superconducting Al reservoirs and InAs semiconductor nanowires. We show clean tunnel characteristics with a current…
A promising scheme for electron microrefrigeration based on ferromagnet-superconductor contacts is presented. In this setup, cooling power densities up to 600 nW/$\mu$m$^2$ can be achieved leading to electronic temperature reductions…
We present a simple on-chip electronic thermometer with the potential to operate down to 1 mK. It is based on transport through a single normal-metal - superconductor tunnel junction with rapidly widening leads. The current through the…
Quantum technology promises revolutionizing applications in information processing, communications, sensing, and modelling. However, efficient on-demand cooling of the functional quantum degrees of freedom remains a major challenge in many…
The design and operation of an electronic cooler based on a combination of superconducting tunnel junctions is described. The cascade extraction of hot-quasiparticles, which stems from the energy gaps of two different superconductors,…
Fragile quantum effects such as single electron charging in quantum dots or macroscopic coherent tunneling in superconducting junctions are the basis of modern quantum technologies. These phenomena can only be observed in devices where the…
The frontiers of quantum electronics have been linked to the discovery of new refrigeration methods since the discovery of superconductivity at a temperature around $4\,$K, enabled by the liquefaction of helium. Since then, the advances in…
Nanoscale electromechanical coupling provides a unique route towards control of mechanical motions and microwave fields in superconducting cavity electromechanical devices. Though their successes in utilizing the optomechanical or…
Efficient electron-refrigeration based on a normal-metal/spin-filter/superconductor junction is proposed and demonstrated theoretically. The spin-filtering effect leads to values of the cooling power much higher than in conventional…
We propose a thermoelectric cooling device based on an atomic-sized junction. Using first-principles approaches, we investigate the working conditions and the coefficient of performance (COP) of an atomic-scale electronic refrigerator where…
The qualities of electron refrigeration by means of tunnel junctions between superconducting and normal--metal electrodes are studied theoretically. A suitable approximation of the basic expression for the heat current across those tunnel…
We study theoretically a process of cooling electrons using a superconducting tunnel junction with a $\pi$ phase difference and a usual insulator or a ferroelectric in-between, and an array of such junctions with ferroelectric layers…