118 research outputs found
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 with the rf-frequency and 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
BiSrCaCuO 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
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