Imaging the effect of drive on the low-field vortex melting phenomenon in Ba0.6K0.4Fe2As2 single crystal

Abstract

Self-field imaging of current distribution in Ba0.6K0.4Fe2As2 superconductor is used to study the effect of drive on the low-field vortex solid to liquid melting phase transformation. At low fields, the current induced drive on the vortices aids in thermally destabilizing the vortex state thereby shifting the low field melting phase boundary. We show that the current induced drive shifts solid-liquid boundaries and prepones the vortex melting phenomenon compared to the equilibrium situation. The analysis shows that for currents above 50 mA, Joule heating effects shift the melting line while below 50 mA, an effective temperature concept for driven system viz., a drive dependent shaking temperature, explains the shift. The observation of a transformation from inhomogeneous to homogeneous current flow in the sample at low fields as a function of the driving force is reconciled via an inverse dependence of the shaking temperature on vortex velocity, which is incorporated in our analysis.

arXiv comment13 pages, 6 figures including Supplementary Information

References in corpus (16)

• Nonequilibrium Critical Phenomena and Phase Transitions into Absorbing States
• Creep and depinning in disordered media
• Depinning and nonequilibrium dynamic phases of particle assemblies driven over random and ordered substrates: a review
• Moving glass phase of driven lattices
• Instabilities and disorder-driven first-order transition of the vortex lattice
• Dynamic instabilities and memory effects in vortex matter
• Low temperature specific heat of the hole-doped Ba_{0.6}K_{0.4}Fe_2As_2 single crystals and electron-doped SmFeAsO_{0.9}F_{0.1} samples
• Fully Gapped Superconducting State Based on a High Normal State Quasiparticle Density of States in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Single Crystals
• Low-Field Phase Diagram of Layered Superconductors: The Role of Electromagnetic Coupling
• Vortex Dynamics and Defects in Simulated Flux Flow
• Random Organization and Plastic Depinning
• Driven Dynamics of Periodic Elastic Media in Disorder
• Dynamic Melting and Decoupling of the Vortex Lattice in Layered Superconductors
• Vortex nanoliquid in high-temperature superconductors
• Critical behavior at de-pinning of a driven disordered vortex matter in 2H-NbS2
• Planar pinning induced, lowering of vortex dimensionality and low field melting in a single crystal of Ba0.6K0.4Fe2As2