Evidence for line vortices inBi2Sr2

Lior Klein

¹

,

E.R. Yacoby

²

,

Y. Yeshurun

³

et al.

Entropy, vortex interactions, and the phase diagram of heavy-ion-irradiatedBi2Sr2CaCuBeek1, Kończykowski2, Drost3 et al. 2000Phys. Rev. BSelf Cite403290View full textAdd to dashboardCite

“…Note that, according to Eqs. (3)(4)(5)(6), ∂M rev /∂ ln B is equal to the difference between two large terms:…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] The effect of the ion tracks is twofold. First, the destruction of superconductivity within the columnar defect core, the radius of which is comparable to the superconducting coherence length ξ, leads to a large reduction of the mixed state free energy [14][15][16][17][18] arising from the pinning of the two-dimensional pancake vortices in the superconducting layers 19,20 by the columns.…”

“…5 Second, the linear geometry of the ion tracks results in the effective alignment of the pancake vortices along the tracks, and the re-establishment of interlayer superconducting phase coherence at temperatures and fields where the unirradiated material behaves as a stack of nearly decoupled superconducting layers. 4,7,[22][23][24][25] The pancake vortex alignment is manifest in the angular dependence of the transport properties of the irradiated superconductor, 4,6 as well as in measurements of the c-axis conductivity (perpendicular to the superconducting layers) 9,10,26,27 and of the field at which the Josephson plasma resonance occurs in the range 24 -45 GHz. 11,12,28,29 Measurements of the Josephson plasma resonance and of the c-axis conductivity, 26,27 which have the advantage of directly probing the Josephson critical current and the cosine of the average phase difference between layers, show the existence, in the heavy-ion irradiated layered superconductor Bi 2 Sr 2 CaCu 2 O 8+δ , of a regime B l (T ) < B < B h (T ) in the vortex liquid state in which interlayer superconducting phase coherence increases as the magnetic field is increased (i.e.…”

Evidence for vortex staircases in the whole angular range due to competing correlated pinning mechanisms

“…As threedimensional vortex configurations cannot be directly observed, our knowledge is mostly based on the analysis of the angular dependence of magnetization, susceptibility, or transport data. [1][2][3][4][5][6][7][8][9][10][11] According to theoretical models, 12,13 when the angle between the applied field H and the defects is smaller than the lock-in angle L vortices remain locked into the defects thus producing a transverse Meissner effect. For tilt angles larger than L and smaller than a trapping angle T , vortices form staircases with segments pinned into different defects and connected by unpinned or weakly pinned kinks.…”

Shift of the surface-barrier part of the irreversibility line due to columnar defects in Bi2Sr2CaCu2O8 thin films

“…They can not support undissipative current flow with large enough density. In crystals and films of Bi 2 Sr 2 CaCu 2 O 8 the critical current density is very low in a wide area of magnetic field and temperature, from ∼ 0.5T c to T c (see for example [1,2]). In this area the surface or edge barriers of different types can manifest themselves.…”