Uniaxial linear resistivity of superconducting La1.905Ba0.095CuO4

Abstract

We present an experimental study of the anisotropic resistivity of superconducting La2−xBaxCuO4 with x = 0.095 and transition temperature Tc = 32 K. In a magnetic field perpendicular to the CuO2 layers, H ⊥ , we observe that the resistivity perpendicular to the layers, ρ ⊥ , becomes finite at a temperature consistent with previous studies on very similar materials; however, the onset of finite parallel resistivity, ρ , occurs at a much higher temperature. This behavior contradicts conventional theory, which predicts that ρ ⊥ and ρ should become finite at the same temperature. Voltage vs. current measurements near the threshold of voltage detetability indicate linear behavior perpendicular to the layers, becoming nonlinear at higher currents, while the behavior is nonlinear from the onset parallel to the layers. These results, in the presence of moderate H ⊥ , appear consistent with superconducting order parallel to the layers with voltage fluctuations between the layers due to thermal noise. In search of uncommon effects that might help to explain this behavior, we have performed diffraction measurements that provide evidence for H ⊥ -induced charge and spin stripe order. The field-induced decoupling of superconducting layers is similar to the decoupled phase observed previously in La2−xBaxCuO4 with x = 1/8 in zero field.

Emergence of charge order from the vortex state of a high-temperature superconductor

“…Indeed, a competition between superconductivity and charge order has also been argued 6,[15][16][17] to provide a natural explanation of the field-enhanced spin and charge orders in La-214 (refs 1,3-6) and LDOS modulations in Bi-2212 (refs 2,7). Despite possible differences in the morphology of the charge order that may depend on the crystallographic structures and on the level of disorder in different families of cuprates, the above experiments and the results in YBa 2 Cu 3 O y are all consistent with the idea that a magnetic field applied perpendicular to the CuO 2 planes generates vortices around which fluctuating or weakly pinned, short-range charge order is revitalised.…”

“…Despite the mounting evidence for a charge-ordering instability in virtually all cuprate families 2,6,[8][9][10][11]23,[26][27][28][29][30] , there is still a long way to go before elucidating the importance of this instability in determining the properties of the cuprates. Neither the possibility of an intertwining of the charge and superconducting order parameters 31 nor the possibility of a direct relationship between the two orders 32,33 can be addressed by the present results.…”

“…T he enhancement of spin-stripe order by a magnetic field in [3][4][5][6][7] . Recently, the discovery of charge order in YBa 2 Cu 3 O y appearing only for fields perpendicular to the copper-oxide planes sufficiently strong to be detrimental to superconductivity 8 , as well as the subsequent observation of related charge density wave (CDW) correlations [9][10][11] , has provided further evidence of competition.…”

Spins, stripes, and superconductivity in hole-doped cuprates

“…A test has been performed on LBCO with x = 0.095, a composition for which the stripe order in zero field is very weak. Figure 75 shows that, indeed, application of H ⊥ enhances both charge and spin order [162].…”

Neutron-Scattering Evidence for a Periodically Modulated Superconducting Phase in the Underdoped CuprateLa1.905Ba0.095CuO4Xu1, Stock2, Chi3 et al. 2014Phys. Rev. Lett.Self Cite3014341View full textAdd to dashboardCite

“…Previous neutron scattering measurements provided evidence for weak charge and spin stripe order [22]. The signal is averaged over the sample, so one cannot distinguish between uniformly weak order and macroscopic phase separation, such as occurs in oxygen-doped La 2−x Sr x CuO 4 [23].…”