Nernst effect and disorder in the normal state of high-T_{c} cuprates

TL;DR

This study investigates how disorder affects the Nernst effect in high-Tc cuprates, revealing that disorder extends the fluctuation regime above Tc and can explain variations in the Nernst signal range.

Contribution

It demonstrates that disorder induced by electron irradiation significantly influences the Nernst effect and fluctuation regime in high-Tc cuprates, clarifying the role of intrinsic disorder.

Findings

Disorder expands the fluctuation regime above Tc.

Pure crystals show a narrow Nernst signal range regardless of doping.

Intrinsic disorder explains the enhanced Nernst signal in pseudogap phase.

Abstract

We have studied the influence of disorder induced by electron irradiation on the Nernst effect in optimally and underdoped YBa2Cu3O(7-d) single crystals. The fluctuation regime above T_{c} expands significantly with disorder, indicating that the T_{c} decrease is partly due to the induced loss of phase coherence. In pure crystals the temperature extension of the Nernst signal is found to be narrow whatever the hole doping, contrary to data reported in the low-T_{c} cuprates families. Our results show that the presence of "intrinsic" disorder can explain the enhanced range of Nernst signal found in the pseudogap phase of the latter compounds.