Non-Ohmic electrical transport properties in YBa<sub>2</sub>Cu<sub>3</sub>O<sub>6+x</sub> at various doping levels

Georg Zechner, Ionut Puica, Wolfgang Lang, Khurram Siraj, Johannes D. Pedarnig

Recent experiments with underdoped high-Tc superconductors, like Nernst effect and sensitive diamagnetism measurements, as well as novel angle resolved photoemission data have revealed signatures that resemble those of a superconducting gap at temperatures well above Tc. However, the onset temperature of these effects does not coincide with the previously discovered, so-called pseudo-gap temperature T* that can be found with a variety of other physical probes. These partially contradicting experimental findings and their intensively discussed theoretical interpretations demonstrate vividly the need for additional experimental probes. We explore a novel experimental approach, the investigation of resistivity and Hall effect in the normal state of YBa2Cu3O6+x (YBCO) beyond the weak electric field limit.

For thin films of YBCO from strongly underdoped to optimally doped we have investigated the in-plane longitudinal and transverse (Hall) conductivities in intense currents. We found a pronounced non-ohmic Hall conductivity in underdoped samples that extends far above Tc. The onset temperature of this effect as a function of doping is discussed with respect to the onset of Nernst effect and to T*.

Electronic Properties of Materials
External organisation(s)
Johannes Kepler Universität Linz
Publication date
Austrian Fields of Science 2012
Solid state physics
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