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We present a detailed analysis of glass transitions induced by pinning particles at random from an equilibrium configuration. We first develop a mean-field analysis based on the study of p-spin spherical disordered models and then obtain…
High-resolution scanning Hall probe microscopy has been used to image vortex configurations in very large periodic arrays of artificial pinning sites. Strong matching effects are seen at fields where either one or two vortices can sit at a…
The vortex lattice is an ideal system to study the competition and interplay between interaction and disorder. New results on 2H-NbSe_2 (in samples of progressively increasing pinning) elucidate how pinning alters the phase boundary…
In magnetic measurements on Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi-2212) single crystals, a general peak with a dynamical feature on both $S-H$ and $S-T$ curves was found with S the magnetic relaxation rate. At higher fields, the…
Vortex matter in layered high-$T_c$ superconductors, including iron-pnictides, undergo several thermodynamic phase transitions due to the complex interplay of pinning energy, thermal energy and elastic energy. Moreover, the presence of…
We have studied the vortex dynamics in the PrFeAsO$_{0.60}$F$_{0.12}$ superconducting sample by dc magnetization and dynamic magnetization-relaxation rate $(Q)$ measurements. The field dependence of the superconducting irreversible…
We explore the smectic liquid crystal order in a cell with a "dirty" substrate imposing random pinnings. Within harmonic elasticity we find a subtle three-dimensional surface disorder-driven transition into a pinned smectic-glass,…
The pinning of vortex lines by an array of nanoparticles embedded inside superconductors has become the most efficient practical way to achieve high critical currents. In this situation pinning occurs via trapping of the vortex-line…
We analyze the vortex dynamics in superconducting thin films with a periodic array of pinning centers. In particular, we study the effect of anisotropy for a Kagom\'e pinning network when longitudinal and transverse transport currents are…
Magnetization and its relaxation have been measured in $Ba(Fe_{1-x}Co_x)_2As_2$ single crystals at various doping levels ranging fromvery underdoped to very overdoped regimes. Sizable magnetization relaxation rate has been observed in all…
Some of the properties of the low temperature vortex-glass phase of randomly-pinned flux lines in 1+1 dimensions are studied. The flux arrays are found to be sensitive to small changes in external parameters such as the magnetic field or…
We study thermal effects on pinning and creep in type-II superconductors where vortices interact with a low density $n_p$ of strong point-like defects with pinning energy $e_p$ and extension $\xi$, the vortex core size. Defects are…
A controlled local enhancement of superconductivity yields unexpected modifications in the vortex dynamics. This local enhancement has been achieved by designing an array of superconducting Nb nanostructures embedded in a V superconducting…
We report on critical currents and voltage noise measurements in Niobium strips in the superconducting state, in the presence of a bulk vortex lattice ($B < B_{C2}$) and in the surface superconducting state ($B_{c2}< B < B_{C3}$). For…
Vortex pinning is a crucial factor that determines the critical current of practical superconductors and enables their diverse applications. However, the underlying mechanism of vortex pinning has long been elusive, lacking a clear…
We review the depinning and nonequilibrium phases of collectively interacting particle systems driven over random or periodic substrates. This type of system is relevant to vortices in type-II superconductors, sliding charge density waves,…
Transport studies in a Corbino disk geometry suggest that the Bragg glass phase undergoes a first-order transition into a disordered solid. This transition shows a sharp reentrant behavior at low fields. In contrast, in the conventional…
Triangular arrays of Ni nanotriangles embedded in superconducting Nb films exhibit unexpected dynamical vortex effects. Collective pinning with a vortex lattice configuration different from the expected fundamental triangular "Abrikosov…
The structure and equilibrium properties of a two-dimensional system of superconducting vortices in a periodic pinning potential with square symmetry are studied numerically. For a range of the strength of the pinning potential, the…
Using numerical simulations we study the configurations, dynamics, and melting properties of vortex lattices interacting with elliptical pinning sites at integer matching fields with as many as 27 vortices per pin. Our pinning model is…