Related papers: Attojoule calorimetry of mesoscopic superconductin…
We report highly sensitive specific heat measurement on mesoscopic superconducting loops at low temperature. These mesoscopic systems exhibit thermal properties significantly different from that of the bulk materials. The measurement is…
The authors report magnetic measurements of fluxoid transitions in mesoscopic, superconducting aluminum rings. The transitions are induced by applying a flux to the ring so that the induced supercurrent approaches the critical current. In a…
A microscopic model is constructed which is able to describe multiple magnetic flux transitions as observed in recent ultra-low temperature tunnel experiments on an aluminum superconducting ring with normal metal - insulator -…
We have experimentally investigated the magnetisation of a mesoscopic aluminum loop at temperatures well below the superconducting transition temperature $T_{c}$. The flux quantisation of the superconducting loop was investigated with a…
We study the magnetic interaction between two superconducting concentric mesoscopic Al loops, close to the superconducting/normal phase transition. The phase boundary is measured resistively for the two-loop structure as well as for a…
Fluctuations are important near phase transitions, where they can be difficult to describe quantitatively. Superconductivity in mesoscopic rings is particularly intriguing because the critical temperature is an oscillatory function of…
The new approach to the microscopic description of the phase transitions starting from the only first principles was developed on an example of the transition normal metal-superconductor. This means mathematically, that the free energy is…
The Ginzburg--Landau approach postulates an energy density, together with an interpretation for the supercurrent, and invokes Ohm's law. We consider quasi-one-dimensional nonuniform superconducting loops, either smooth or piecewise uniform,…
The normal/superconducting phase boundary Tc has been calculated for mesoscopic loops, as a function of an applied perpendicular magnetic field H. While for thin-wire loops and filled disks the Tc(H) curves are well known, the intermediate…
The magnetic coupling between two concentric mesoscopic superconductors with non-zero thickness is studied using the nonlinear Ginzburg-Landau theory. We calculated the free energy, the expelled field, the total field profile, the…
We present the first measurements of thermal signatures of the Little-Parks effect using a highly sensitive nanocalorimeter. Small variations of the heat capacity $C\_p$ of 2.5 millions of non interacting micrometer-sized superconducting…
The critical fluctuations in a mesoscopic superconducting ring are studied within the Ginzburg-Landau approach. The nonlocal conductivity as well as the specific heat are calculated as functions of the magnetic flux $\Phi$ through the ring.…
We study the influence of thermal fluctuations on the magnetic behavior of square mesoscopic superconductors. The strength of thermal fluctuations are parameterized using the Ginzburg number, which is small ($G_i \approx 10^{-10}$) in…
A dc voltage changed periodically with magnetic field is observed on segments of asymmetric aluminum loop without any external dc current at temperatures corresponded to superconducting transition. According to this experimental result a…
We observe a maximum in the conductance of Aluminum / n-GaAs junctions at temperatures 20 mK lower than the superconducting transition temperature. This is the first observation of a non- monotonic behavior of the conductance near the…
We report magnetic measurements up to 1200 K on three different multi-walled carbon nanotube mat samples using Quantum Design vibrating sample magnetometers. Three different samples prepared from arc discharge or chemical vapor deposition…
We have studied the nucleation of superconductivity in a mesoscopic Al loop, enclosing magnetic dot with perpendicular magnetization. The superconducting phase boundary Tc(B), determined from transport measurements, is asymmetric with…
The heat capacity $C_{p}$ of an array of independent aluminum rings has been measured under an external magnetic field $\vec{H}$ using highly sensitive ac-calorimetry based on a silicon membrane sensor. Each superconducting vortex entrance…
In the framework of the Ginzburg-Landau equation, the temperature dependence of the upper critical field of small ring-like superconductors is studied. At equilibrium small parts of the phase diagram show paramagnetism for width / radius…
Rings are a model system for studying phase coherence in one dimension. Superconducting rings have states with uniform phase windings that are integer multiples of 2$\pi$ called fluxoid states. When the energy difference between these…