Vortex lattice dynamics in a-NbGe detected by mode-locking experiments

We observed mode-locking (ML) of rf-dc driven vortex arrays in a superconducting weak pinning a-NbGe film. The ML voltage shows the expected scaling $V\propto f\sqrt{B}$ with $f$ the rf-frequency and $B$ the magnetic field. For large dc-velocity (corresponding to a large ML frequency), the ML current step width exhibits a squared Bessel function dependence on the rf-amplitude as predicted for ML of a lattice moving elastically through a random potential.Comment: 2 pages, 2 figures. Contribution to M2S-HTSC Ri

Observation of correlated vortex flow in NbSe2 with magnetic decoration

Article / Letter to editorLeids Instituut Onderzoek Natuurkund

Depinning and anisotropic order in flowing and static vortex lattices in NbSe_2 studied with magnetic decoration

Quantum Matter and Optic

Transport properties of vortices in easy flow channels: A Frenkel-Kontorova study

Quantum Matter and Optic

Vortex liquid correlations induced by in-plane field in underdoped Bi2Sr2CaCu2O8+d

By measuring the Josephson Plasma Resonance, we have probed the influence of an in-plane magnetic field on the pancake vortex correlations along the c-axis in heavily underdoped Bi2Sr2CaCu2O8+d (Tc = 72.4 +/- 0.6 K) single crystals both in the vortex liquid and in the vortex solid phase. Whereas the in-plane field enhances the interlayer phase coherence in the liquid state close to the melting line, it slightly depresses it in the solid state. This is interpreted as the result of an attractive force between pancake vortices and Josephson vortices, apparently also present in the vortex liquid state. The results unveil a boundary between a correlated vortex liquid in which pancakes adapt to Josephson vortices, and the usual homogeneous liquid.Comment: 2 pages, submitted to the Proceedings of M2S HTSC VIII Dresde

Magnetization Decay due to Vortex Phase Boundary Motion in BSCCO

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 time window is identified during which the decay of the induction is controlled by the slow propagation of the phase transformation front across the sample.Comment: 2 pages, 3 figures Paper submitted to the conference proceedings of M2S-2000 Houston T

Magnetic relaxation in the "Bragg-glass" phase in BSCCO

Magnetic relaxation in the Bragg-glass phase of overdoped Bi_2Sr_2CaCu_2O_8 crystals was investigated using time-resolved magneto-optical visualisation of the flux distribution. This has permitted us to extract the current-voltage characteristic, which can be well described by a power-law, although fits to a stretched exponential E \sim \exp(- j_{c} / j)^{\mu} with 0.3 < \mu < 0.8 are possible at long times in excess of 100 s.Comment: 2 pages, 3 figures submitted to conference proceedings of M2S-2000 Houston T

Elastic deformations in field-cooled vortex lattices in NbSe2

Quantum Matter and Optic

Vortex lattice melting in multilayers with variable anisotropies

Quantum Matter and Optic