Faculté des sciences

Pseudogap and precursor superconductivity in underdoped cuprate high temperature superconductors: A far-infrared ellipsometry study

Dubroka, Adam ; Yu, Li ; Munzar, Dominik ; Kim, KyungWan ; Rössle, Matthias ; Malik, Vivek Kumar ; Lin, C.T. ; Keimer, B. ; Wolf, Th. ; Bernhard, Christian

In: The European Physical Journal - Special Topics, 2010, vol. 188, no. 1, p. 73-88

With the technique of infrared ellipsometry we performed a detailed study of the temperature- and doping dependence of the c-axis response of a series of YBa₂Cu₃O7−δ single crystals. In particular, we explored the anomalous electronic properties at temperatures above the macroscopic superconducting transition temperature, T c, whose conflicting... Plus

Ajouter à la liste personnelle
    Summary
    With the technique of infrared ellipsometry we performed a detailed study of the temperature- and doping dependence of the c-axis response of a series of YBa₂Cu₃O7−δ single crystals. In particular, we explored the anomalous electronic properties at temperatures above the macroscopic superconducting transition temperature, T c, whose conflicting explanations range from a precursor superconducting state to electronic correlations that compete with superconductivity. We show that the c-axis spectra provide evidence that both kinds of correlations are present and that their contributions can be disentangled based on an analysis with a so-called multilayer-model. We find that the onset temperature, T *, and the energy scale, ΔPG, of the competing pseudogap increase rapidly towards the underdoped side whereas they vanish on the overdoped side. In addition, we provide evidence that in a strongly underdoped sample the precursor superconducting correlations develop below an onset temperature, T ons, that is considerably lower than T * but still much higher than T c.