Disentangling Cooper-pair formation above the transition temperature from the pseudogap state in the cuprates

TitleDisentangling Cooper-pair formation above the transition temperature from the pseudogap state in the cuprates
Publication TypeJournal Article
Year of Publication2011
AuthorsKondo T, Hamaya Y, Palczewski AD, Takeuchi T, Wen JS, Xu ZJ, Gu GD, Schmalian J, Kaminski A
Journal TitleNature Physics
Volume7
Pages21-25
Date Published01
Type of ArticleArticle
ISBN Number1745-2473
Accession NumberISI:000285501100010
Keywordsdensity, dynamics, fluctuations, gaps, T-C SUPERCONDUCTORS, underdoped bi2sr2cacu2o8+delta
Abstract

The discovery of the pseudogap in the cuprates(1-3) created significant excitement as it was believed to be a signature of pairing(4), in some cases above room temperature. Indeed, a number of experiments detected phase-fluctuating superconductivity above the transition temperature T-c (refs 5-9). However, several recent experiments reported that the pseudogap and superconducting state are characterized by different energy scales(10-14), and probably compete with each other(15,16), leaving open the question of whether the pseudogap is caused by pair formation. Here we report the discovery of a spectroscopic signature of pair formation and demonstrate that in a region commonly referred to as the pseudogap, two distinct states coexist: one that is due to pair formation and persists to an intermediate temperature T-pair < T* and a second-the 'proper' pseudogap-characterized by the loss of spectral weight and anomalies in transport properties that extends up to T*. T-pair has a value around 120-150 K even for materials with very different T-c values and it probably sets a limit on the highest attainable T-c in the cuprates.

URL<Go to ISI>://000285501100010
DOI10.1038/nphys1851
Alternate JournalNat. Phys.