Related papers: Sub-50 mK electronic cooling with large-area super…
Identifying materials and devices which offer efficient thermoelectric effects at low temperature is a major obstacle for the development of thermal management strategies for low-temperature electronic systems. Superconductors cannot offer…
We demonstrate shadow evaporation-based fabrication of high-quality ultrasmall normal metal -- insulator -- superconductor tunnel junctions where the thickness of the superconducting electrode is not limited by the requirement of small…
We have used normal metal-insulator-superconductor tunnel junctions as thermometers at sub-Kelvin temperatures to study the electron-phonon (e-p) interaction in thin Aluminum films doped with Manganese, as a function of Manganese…
Using the Eliashberg strong coupling theory with vertex correction, we calculate maps of transition temperatures (T$_{c}$) of electron-phonon superconductors in full parameter space. The maximums of transition temperatures for…
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…
In this work, we investigate the thermoelectric properties of a hybrid junction realised coupling surface states of a three-dimensional topological insulator with a conventional $s$-wave superconductor. We focus on the ballistic devices and…
In the presence of Joule heating, the electronic temperature in a metallic resistor placed at sub-Kelvin temperatures can significantly exceed the phonon temperature. Electron cooling proceeds mainly through two processes: electronic…
We present radio-frequency thermometry based on a tunnel junction between a superconductor and proximitized normal metal. It allows operation in a wide range of biasing conditions. We demonstrate that the standard finite-bias quasiparticle…
We propose a solid state refrigeration technique based on repeated adiabatic magnetization/demagnetization cycles of a superconductor which acts as the working substance. The gradual cooling down of a substrate (normal metal) in contact…
Raman studies on Ca4Al2O5.7Fe2As2 superconductor in the temperature range of 5 K to 300 K, covering the superconducting transition temperature Tc ~ 28.3 K, reveal that the Raman mode at ~ 230 cm-1 shows a sharp jump in frequency by ~ 2 %…
We report on measurements of dissipation and frequency noise at millikelvin temperatures of nanomechanical devices covered with aluminum. A clear excess damping is observed after switching the metallic layer from superconducting to the…
We present a brief review of some recent work on the problem of highest achievable temperature of superconducting transition $T_c$ in electron-phonon systems. The discovery of record-breaking values of $T_c$ in quite a number of hydrides…
We consider a model NISIN system with two junctions in series, where N is a normal metal, S is a superconductor and I is an insulator. We assume that the resistance of the first junction is high, while the resistance of the second one is…
We have studied hybrid superconducting micro-coolers made of a double Superconductor-Insulator-Normal metal tunnel junction. Under subgap conditions, the Andreev current is found to dominate the single-particle tunnel current. We show that…
The temperature dependence of the I-V characteristics of many single-electron tunneling devices enable thermometer operation of these systems. We investigate two normal conducting kinds of them, {\sl (a)} a single junction in a…
Although a superconductor has no DC losses, a superconducting system does have significant losses, especially when it comes to power supply. Here, we study two different power supply systems. The first, a conventional one, consists of a…
We demonstrate quantum limited electronic refrigeration of a metallic island in a low temperature micro-circuit. We show that matching the impedance of the circuit enables refrigeration at a distance, of about 50 um in our case, through…
We demonstrate highly transparent silicon-vanadium and silicon-aluminum tunnel junctions with relatively low sub-gap leakage current and discuss how a trade-off typically encountered between transparency and leakage affects their…
We have investigated electronic cooling of suspended nanowires with SINIS tunnel junction coolers. The suspended samples consist of a free standing nanowire suspended by four narrow ($\sim$ 200 nm) bridges. We have compared two different…
With a generic model for the electron-phonon spectral density, two simple expressions are derived to estimate the transition temperature and gap-to-temperature ratio in conventional superconductors. They entail that on average the numerical…