Comment on Visualization of the interplay between high-temperature superconductivity, the pseudogap and impurity resonances

TL;DR

This paper critiques and offers an alternative interpretation of STM data on impurity resonances in high-temperature superconductors, emphasizing the complex interplay between superconductivity, pseudogap phenomena, and impurities.

Contribution

It provides a critical analysis of recent STM findings and proposes a new interpretation of impurity resonances in high-Tc superconductors.

Findings

Impurity resonances coexist with the superconducting gap below Tc.

Resonances survive above Tc without change, challenging previous interpretations.

The paper suggests alternative explanations for the observed data.

Abstract

In a recent letter, Chatterjee et al. (Nature Phys. 4, 108 (2008)) reported tunnelling data obtained below and above the critical temperature (Tc = 15 K) by STM in overdoped Bi2-yPbySr2CuO6+x (Bi2201) and some interpretations of the data1. The main experimental findings of their work are observations of native-impurity resonances which coexist spatially with the superconducting (SC) gap below Tc and survive unchanged on warming through Tc. No doubts, the data in the letter are an important piece of information for assembling the high-Tc SC jigsaw puzzle; however, there are inaccuracies in the discussion. In addition, I propose another interpretation of the data.