Uniaxial linear resistivity of superconducting La(1.905)Ba(0.095)CuO(4) induced by an external magnetic field

TL;DR

This study investigates the anisotropic resistivity of superconducting La(2-x)Ba(x)CuO(4) under magnetic fields, revealing unconventional behavior and field-induced stripe order that challenge existing theories of superconductivity.

Contribution

It provides experimental evidence of anisotropic resistivity behavior and field-induced stripe order in La(2-x)Ba(x)CuO(4), highlighting deviations from conventional superconductivity models.

Findings

ho(perp) becomes finite at a certain temperature under magnetic field.

ho(par) becomes finite at a higher temperature than ho(perp).

Evidence of H(perp)-induced charge and spin stripe order.

Abstract

We present an experimental study of the anisotropic resistivity of superconducting La(2-x)Ba(x)CuO(4) with x=0.095 and transition temperature Tc=32 K. In a magnetic field perpendicular to the CuO(2) layers, H(perp), we observe that the resistivity perpendicular to the layers, \rho(perp), becomes finite at a temperature consistent with previous studies on very similar materials; however, the onset of finite parallel resistivity, \rho(par), occurs at a much higher temperature. This behavior contradicts conventional theory, which predicts that \rho(perp) and \rho(par) should become finite at the same temperature. Voltage vs. current measurements near the threshold of voltage detectability 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(perp), 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(perp)-induced charge and spin stripe order. The field-induced decoupling of superconducting layers is similar to the decoupled phase observed previously in La(2-x)Ba(x)CuO(4) with x=1/8 in zero field.