Scaling of the longitudinal and Hall resistivities from vortex motion inYBa2Cu3

Abstract

We measure the longitudinal (p xx ) and Hall (p xv ) resistivities as a function of magnetic field and temperature in the mixed state of epitaxial YBa2Cu3C>7 films. We observe a striking power-law behavior p xy {T) oc [p xx (T)] a at fixed field, with a -1.7 ±0.2. Our results link the Hall behavior to collective behavior in the presence of pinning. In addition, this power-law dependence is consistent with new calculations for the vortex-glass transition, and therein may provide the first measurement of a new critical exponent.

Anomalous scaling behavior in a mixed-state Hall effect of a cobalt-doped BaFe2As2epitaxial film with a high critical current density over 1 MA/cmSato1, Katase2, Kang3 et al. 2013Phys. Rev. B17170View full textAdd to dashboardCite

“…2.0; they are between 1.7-1.8 and independent of the applied magnetic field up to at least 9 T. These β values are lower than those reported for Ba(Fe 1-x Co x ) 2 As 2 single crystals with β = 3.0-3.4 for x = 0.08 and β = 2.0 ± 0.2 for x = 0.10, [39] but are comparable to those of YBCO epitaxial films with strong pinning centers. [22] Similar β behaviors with magnetic fields (i.e., no variation with H) are also observed in BSCCO single crystals [24] and MgB 2 films, [27] in which weak pinning centers are introduced.…”

“…Unlike cuprate superconductors exhibiting 1.0 < β < 2.0, [22,23,25,26] the sign of ρ xy in this study does not reverse in either the T or the H sweep results. Wang's theory [32] predicts that the scaling behavior exhibiting β < 2.0 occurs after a sign reversal, which is inconsistent with the present results.…”

“…The above behavior for a Ba(Fe 1-x Co x ) 2 As 2 film, in which a small and constant β is maintained under various magnetic fields, is generally reported for superconductors with strong pinning centers such as twinned YBCO epitaxial films, [22] irradiated YBCO single crystals, [25] and irradiated Tl 2 Ba 2 CaCu 2 O 8 films. [23,40] Unlike the T sweep results (Fig.…”

“…In fact, the β values of most cuprate superconductors exhibiting strong pinning are 1.0-1.8, which are considerably less than 2.0. [22,23,25,26] Based on the Wang's theory, [32] our experimental results with β = 1.7-1.82 indicate that strong pinning centers effectively work for the T sweep in the entire H region examined in this study. The strong pinning centers are also effective for the H sweep only in the low T (< 14 K) region, but the pinning strength rapidly weakens as T increases and approaches T c .…”

“…The behavior of the β value has actively been discussed in relation to the superconducting and vortex pinning mechanisms. [22][23][24][25][26][27] Although sign reversal of ρ xy has been observed, its origin remains controversial. [28][29][30] Vinokur et al [31] considered the momentum balance and proposed a model where a system of interacting vortices under quenched disorders and thermal noises follows a universal scaling law with a universal β = 2.0.…”