Effect of pseudogap formation on the penetration depth of underdoped high $T_c$ cuprates

TL;DR

This paper models how pseudogap formation affects the penetration depth in underdoped high-Tc cuprates, highlighting the role of Fermi surface reconstruction and correlations, and validates the theory with experimental data.

Contribution

It introduces a model based on the resonating valence bond spin liquid to describe pseudogap effects on penetration depth, emphasizing Fermi surface reconstruction and correlation effects.

Findings

Sharp drop in superfluid density at T=0 due to Fermi surface reconstruction

The linear low-temperature slope remains unchanged by pseudogap formation

Validation of the model with experimental data on Bi-based cuprates

Abstract

The penetration depth is calculated over the entire doping range of the cuprate phase diagram with emphasis on the underdoped regime. Pseudogap formation on approaching the Mott transition, for doping below a quantum critical point, is described within a model based on the resonating valence bond spin liquid which provides an ansatz for the coherent piece of the Green's function. Fermi surface reconstruction, which is an essential element of the model, has a strong effect on the superfluid density at T=0 producing a sharp drop in magnitude, but does not change the slope of the linear low temperature variation. Comparison with recent data on Bi-based cuprates provides validation of the theory and shows that the effects of correlations, captured by Gutzwiller factors, are essential for a qualitative understanding of the data. We find that the Ferrell-Glover-Tinkham sum rule still holds and we compare our results with those for the Fermi arc and the nodal liquid models.