Related papers: "Vortex-melting front" in thin superconductors wit…
We have investigated the healing of transient disordered vortex states injected into a superconducting sample during the field ramping process in isothermal M-H measurements as a prescription to comprehend the modulation in the state of…
Superconductors have two key characteristics. They expel magnetic field and they conduct electrical current with zero resistance. However, both properties are compromised in high magnetic fields which can penetrate the material and create a…
We report on a Monte-Carlo study of two-dimensional Ginzburg-Landau superconductors in a magnetic field which finds clear evidence for a first-order phase transition characterized by broken translational symmetry of the superfluid density.…
Disorder induced melting, where the increase in positional entropy created by random pinning sites drives the order-disorder transition in a periodic solid, provides an alternate route to the more conventional thermal melting. Here, using…
The melting of the Abrikosov vortex lattice in a 2D type-II superconductor at high magnetic fields is studied analytically within the framework of the phenomenological Ginzburg-Landau theory. It is shown that local phase fluctuations in the…
The peak effect in weakly pinned superconductors is accompanied by metastable vortex states. Each metastable vortex configuration is characterized by a different critical current density J_c, which mainly depends on the past thermomagnetic…
We report torque magnetization measurements in regions of the mixed state phase diagram (${\bf B}\sim\mu_o{\bf H}_{c2}$ and T$_c$/$10^3$) of the organic superconductor $\kappa-$(ET)$_2$Cu(NCS)$_2$ where quantum fluctuations are expected to…
In this work we revisit the vortex matter phase diagram in layered superconductors solving still open questions by means of AC and DC local magnetic measurements in the paradigmatic Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$ compound. We show that…
Physical properties of the vortex solid phase formed in the second Landau level (2LL), which may be stabilized by strong paramagnetic pairbreaking (PPB), are examined in type II limit with no magnetic screening. First, it is shown that the…
We carry out MC studies of 2D superconducting networks, in an applied magnetic field, for square and honeycomb geometries. We consider both dilute systems (f=1/q) and systems near full frustration (f=1/2-1/q). For the dilute case (which…
We use Monte Carlo simulations of the 3D uniformly frustrated XY model, with uncorrelated quenched randomness in the in-plane couplings, to model the effect of random point pins on the vortex line phases of a type II superconductor. We map…
In the framework of London theory we study the novel magnetic state in two-component superconductors with finite density of fractional flux vortices stabilized near the surface. We show that the process of vortex entry into the…
In type-II superconductors exposed to magnetic fields between upper and lower critical values, $H_{c1}$ and $H_{c2}$, penetrating magnetic flux forms a lattice of vortices whose motion can induce dissipation. Consequently, the magnetization…
Type-II superconductors under magnetic fields are in a quantum coherent non-dissipative state as long as vortices remain pinned. Dissipation appears when vortices depin, eventually driven by thermal fluctuations. This can be associated to a…
Theory of melting of the vortex lattice in type II superconductors in the framework of Ginzburg - Landau approach is presented. The melting line location is determined and magnetization and specific heat jumps along it are calculated. The…
Topological defects such as dislocations and disclinations are predicted to determine the twodimensional (2-D) melting transition. In 2-D superconducting vortex lattices, macroscopic measurements evidence melting close to the transition to…
The angular dependence of the first-order phase transition (FOT) in the vortex lattice in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$ crystals was investigated by a low frequency AC shielding technique (with the AC field $\parallel c$), in which the…
Imaging of flux vortices in high quality MgB$_2$ single crystals has been successfully performed in a commercial Field Emission Gun-based Transmission Electron Microscope. In Cryo-Lorentz Microscopy, the sample quality and the vortex…
We identify a new regime of decay of the irreversible magnetization in clean Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$ crystals, at induction values close to the ``second peak field'' at which the bulk critical current density steeply increases. A…
The influence of antiferromagnetic order on the mixed state of a superconductor may result in creation of spin-flop domains along vortices. This may happen when an external magnetic field is strong enough to flip over magnetic moments in…