Tunnel and thermal c-axis transport in BSCCO in the normal and pseudogap state

TL;DR

This paper develops a model for c-axis transport in Bi2212 cuprates, accurately describing resistivity in various doping and voltage conditions, including the pseudogap state, by considering the effects of two barriers.

Contribution

The authors introduce a parameter-free extension of their model to account for voltage bias effects on c-axis transport in Bi2212, covering normal, pseudogap, and superconducting states.

Findings

Model accurately fits normal state resistivity across doping levels.

Extended model describes voltage-dependent resistivity above T* and below Tc.

Reproduces differential conductance curves in mesa experiments.

Abstract

We consider the problem of c-axis transport in double-layered cuprates, in particular with reference to Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ compounds. We exploit the effect of the two barriers on the thermal and tunnel transport. The resulting model is able to describe accurately the normal state c-axis resistivity in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$, from the underdoped side up to the strongly overdoped. We extend the model, without introducing additional parameters, in order to allow for the decrease of the barrier when an external voltage bias is applied. The extended model is found to describe properly the c-axis resistivity for small voltage bias above the pseudogap temperature $T^{*}$, the c-axis resistivity for large voltage bias even below $T_c$, and the differential $dI/dV$ curves taken in mesa structures.