Related papers: Multiple fluxoid transitions in mesoscopic superco…
We present a scanning probe technique for measuring the dynamics of individual fluxoid transitions in multiply connected superconducting structures. In these measurements, a small magnetic particle attached to the tip of a silicon…
We have measured the dynamics of individual magnetic fluxoids entering and leaving thin film, photolithographically patterned rings of underdoped high-temperature superconductor BSCCO using a variable sample temperature scanning SQUID…
An experimental and theoretical investigation was made of flux jumps and irreversible magnetization curves of mesoscopic Al superconducting rings. In the small magnetic field region the change of vorticity with magnetic field can be larger…
We use the Ginzburg-Landau theory near the transition temperature in order to examine the behavior of an inhomogeneous superconductor in the presence of a magnetic field. We find that a transition from type I to type II superconductivity…
A microscopic analysis of the superconducting quantum critical point realized via a pair-breaking quantum phase transition is presented. Finite temperature crossovers are derived for the electrical conductivity, which is a key probe of…
The electromagnetic properties of superconductors near a ferromagnetic instability are investigated by means of a generalized Ginzburg-Landau theory. It is found that the magnetic flux expulsion capability of the superconductor gets…
Recent advances in cooling techniques make now possible the experimental study of quantum phase transitions, which are transitions near absolute zero temperature accessed by varying a control parameter. A paradigmatic example is the…
Phase transitions in superconducting mesoscopic disks have been studied over the H-T phase diagram through heat capacity measurement of an array of independent aluminium disks. These disks exhibit non periodic modulations versus H of the…
Phase transitions between different (i.e. giant and multi-vortex) superconducting states and between the superconducting-normal state of mesoscopic disks and rings are studied in the presence of an external magnetic field by solving the two…
A model of two-species bosons moving on the sites of a lattice is studied at nonzero temperature, focusing on magnetic order and superfluid-insulator transitions. Firstly, Landau theory is used to find the general structure of the phase…
We study the finite-size and boundary effects on a time-reversal-symmetry breaking p-wave superconducting state in a mesoscopic disc geometry using Ginzburg-Landau theory. We show that, for a large parameter range, the system exhibits…
At low temperatures, iron monosilicide is a strongly correlated narrow-gap semiconductor. A first order transition to metal state induced by magnetic field was observed for the first time at 355 T in Ref. [Yu. B. Kudasov et al., JETP Lett.…
Starting from the Ginzburg-Landau energy functional, we discuss how the presence of two order parameters and the coupling between them influence a superconducting ring in the fluctuative regime. Our method is exact, but requires numerical…
In these lectures, superconductivity in impure thin films close to the absolute zero of temperature is discussed. The behavior as function of the applied magnetic field and the amount of impurities suggests the presence of a…
We study the flux-driven superconductor-metal transition in ultrasmall cylinders observed experimentally by Liu {\em et.al.}(Science 294, 2332 (2001)). Where $T_c\to 0$, there is a quantum critical point, and a large fluctuation…
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 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…
Systems which rapidly evolve through symmetry-breaking transitions on timescales comparable to the fluctuation timescale of the single-particle excitations may behave very differently than under controlled near-ergodic conditions. A…
We derive the Ginzburg-Landau-Wilson theory for the superconducting phase transition in two dimensions and in the magnetic field. Without disorder the theory describes a fluctuation induced first-order quantum phase transition into the…
The fluctuating diamagnetic magnetization Mfl at constant field H as a function of temperature and the isothermal magnetization Mfl vs H are measured in MgB2, above the superconducting transition temperature. The expressions for Mfl in…