Mixed-state Hall effect of YBa2Cu3O7 thin films at high current densities

Non-Ohmic Hall resistivity observed above the critical temperature in the high-temperature superconductorYBa2Cu3O7−δ

“…A similar behavior has been observed previously-although in smaller current densities than in the present work-and has been attributed to the fact that pinning forces are overcome in elevated current densities. 16,18 Our present results for this temperature region do agree with those conclusions and reveal additional effects that becomes noticeable in extremely high current densities. This effects are better evidenced in the Hall conductivity picture, as it is shown below.…”

“…A satisfactory agreement with the theoretical models for layered superconductors based on a microscopic approach 11 or on the time-dependent Ginzburg-Landau ͑TDGL͒ theory 12,13 has been found only with reduction and correction of the self-heating 14 using a pulsed current technique 9,14 and additionally very thin films. 10,15 The influence of high current densities on the Hall effect has been investigated in HTSC, [16][17][18][19][20] with the aim of overcoming the vortex pinning and testing its influence on the Hall anomaly that is observed below T c . An intrinsic non-Ohmic effect above T c was neither explicitly investigated nor fortuitously found in these studies.…”

“…16,18 Our aim is to look for non-Ohmic effects on the Hall conductivity in the upper part of the superconducting transition region and to test whether these effects could be explained as a consequence of the fluctuation suppression in strong electric fields. The results can contribute important information to the long-lasting debate on the origin of the Hall anomaly in HTSC.…”

Non-ohmic Electrical Transport Properties Above the Critical Temperature in Optimally and Underdoped Superconducting YBa2Cu3O6+x

“…A strong non-ohmic effect can be noticed in the region of ρ yx < 0, where the negative minimum is dramatically enhanced at higher electric fields. Such behavior has been observed and discussed previously [10,14,16,34] and has been attributed to the fact that pinning forces are overcome in elevated currents.…”

“…The Hall effect in high current densities has been measured in HTSC [14][15][16][17][18][19] mainly with the aim of overcoming the vortex pinning and to investigate the Hall anomaly that is observed below T c . An intrinsic non-ohmic effect above T c was reported recently [10] and interpreted by the suppression of Aslamazov-Larkin (AL) superconducting fluctuations in high electric fields [20].…”