Local Electrodynamics in Heavy Ion IrradiatedBi2Sr2CaCu2

Abstract

Transport measurements in the flux transformer and c-axis geometries are used to investigate vortex dynamics in heavy ion irradiated BSCCO crystals. In the flux transformer geometry there is a range of fields, temperatures, and angles where the primary and secondary voltages show close correspondence, as observed in YBCO. This occurs because the columnar defects suppress thermal fluctuations and decrease r c. Values for r ab and r c are extracted from the flux transformer data assuming local anisotropic electrodynamics and compared with directly measured c-axis data. Good agreement confirms the validity of local resistivity. This is supported by both measurement configurations indicating that r c vanishes faster than r ab. [S0031-9007(96)00874-5]

Entropy, vortex interactions, and the phase diagram of heavy-ion-irradiatedBi2Sr2CaCuBeek1, Kończykowski2, Drost3 et al. 2000Phys. Rev. B403290View full textAdd to dashboardCite

“…[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.…”

Nonlocal conductivity in high-temperature superconductors

“…Nevertheless, when they perform a Montgomery analysis on their data, they do see discrepancies in the apparent ratio xx (a) / zz (a) . Conversely, measurements by Busch et al 11 on single-crystal BSCCO and by Doyle et al 12 on BSCCO with columnar defects are claimed to be consistent with local resistivity. These seemingly contradictory results could be caused by approximations used in the local analysis 11 and might be resolved by using the full analysis or better suited approximations, such as the one proposed by Levin.…”

Vortex dynamics in heavy-ion-irradiated single crystals ofBi2Sr2CaCu2O8+δandAmmor1, Hong2, Pignon3 et al. 2004Phys. Rev. B

“…The observed Bose-glass behavior in highly anisotropic BSCCO ͑␥ = 380͒ with CD's indicates that the pancake vortices pinned by columnar tracks in heavy-ion-irradiated BSCCO crystals act as well-coupled vortex lines. The 3D coupling of vortices by CD's was demonstrated by the transport measurements in flux transformer geometry 37 and Josephson plasma resonance in BSCCO with CD's. 38 Our observations are in contradiction with the interpretation of the irreversibility in terms of single-pancake depinning from CD's in Ref.…”