Related papers: Superconductivity in Ultrasmall Metallic Grains
A new variational method for studying the equilibrium states of an interacting particles system has been proposed. The statistical description of the system is realized by means of a density matrix. This method is used for description of…
Magnetic properties of dust grains play a fundamental role in their alignment with ambient magnetic fields and magnetic dipole emission. In the radiative torque (RAT) paradigm, superparamagnetic inclusions (SPIs) embedded within dust grains…
When subject to a weak magnetic impurity potential, the order parameter and quasi-particle energy gap of a bulk singlet superconductor are suppressed. According to the conventional mean-field theory of Abrikosov and Gor'kov, the integrity…
`Strange' metals that do not follow the predictions of Fermi liquid theory are prevalent in materials that feature superconductivity arising from electron interactions. In recent years, it has been hypothesized that spatial randomness in…
A systematic study of the superconducting properties in a series of arc-melted Nb-B samples close to the 1:1 composition was carried out. Powder X-ray diffraction (XRD) shows that all samples are both non-stoichiometric, and comprising of…
The present article reports a method for the average grain size evaluation of superconducting nano-particles through their magnetic properties. The use of SQUID magnetometry to determine the average MgB2 particle size was investigated and…
The discovery of superconductivity in 3$d$-transition metal compounds with strong magnetism is interesting but rare. Especially for Mn-based compounds, there exist only very limited materials that show superconductivity. Here, we report the…
We investigate transport in a granular metallic system at large tunneling conductance between the grains, $g_T\gg 1$. We show that at low temperatures, $T\leq g_T\delta $, where $\delta$ is the single mean energy level spacing in a grain,…
Spin imbalance is predicted to lead to suppression of superconductivity. We report phenomena manifesting this effect under spin-polarized quasiparticle currents in ferromagnet-superconductor-ferromagnet single electron transistors. The…
Magnetism and superconductivity often compete for preeminence as a material's ground state, and in the right circumstances the fluctuating remains of magnetic order can induce superconducting pairing. The intertwining of the two on the…
Superconductivity in small metallic specimens is studied with regard to the size dependence of the "parity gap" (Delta_P), a parameter distinguishing between the energy of even and odd number of electrons in the granule. Delta_P is shown to…
We study the mesoscopic fluctuations of thermodynamic observables in a nanosized metallic grain in which the single-particle dynamics are chaotic and the dimensionless Thouless conductance is large. Such a grain is modeled by the universal…
The electrical conductivity induced near the superconducting transition by thermal fluctuations was measured in different granular aluminum films. The seemingly anomalous behavior at high reduced temperatures and magnetic fields is…
The concept of a self-consistent field in the theory of superconductivity based on the diagram method of the time-dependent perturbation theory is presented. It is shown that the well-known Bardeen-Cooper-Schrieffer equation for the order…
Discrete energy levels of ultrasmall metallic grains are extracted in single-electron-tunneling-spectroscopy experiments. We study the response of these energy levels to an external magnetic field in the presence of both spin-orbit…
In the recent experiments the unusual oscillatory magnetoresistance in superconductors was discovered with a periodicity essentially independent on magnetic field direction and even material parameters. The nearly universal period points to…
A general analysis of Meissner effect and spin susceptibility of a uniform superconductor in an asymmetric two-component fermion system is presented in nonrelativistic field theory approach. We found that, the pairing mechanism dominates…
Thermal dust polarization is a powerful tool to probe magnetic fields ($\textbf{B}$) and grain properties. However, a systematic study of the dependence of dust polarization on grain properties in protostellar environments is not yet…
The size of dust grains, $a$, is key to the physical and chemical processes in circumstellar disks, but observational constraints of grain size remain challenging. (Sub)millimeter continuum observations often show a percent-level…
The metallic transition-metal dichalcogenides (TMDCs) are benchmark systems for studying and controlling intertwined electronic orders in solids, with superconductivity developing upon cooling from a charge density wave state. The interplay…