A universal explanation of tunneling conductance in exotic superconductors
2016 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, 31352Article in journal (Refereed) Published
A longstanding mystery in understanding cuprate superconductors is the inconsistency between the experimental data measured by scanning tunneling spectroscopy (STS) and angle-resolved photoemission spectroscopy (ARPES). In particular, the gap between prominent side peaks observed in STS is much bigger than the superconducting gap observed by ARPES measurements. Here, we reconcile the two experimental techniques by generalising a theory which was previously applied to zero-dimensional mesoscopic Kondo systems to strongly correlated two-dimensional (2D) exotic superconductors. We show that the side peaks observed in tunneling conductance measurements in all these materials have a universal origin: They are formed by coherence-mediated tunneling under bias and do not directly reflect the underlying density of states (DOS) of the sample. We obtain theoretical predictions of the tunneling conductance and the density of states of the sample simultaneously and show that for cuprate and pnictide superconductors, the extracted sample DOS is consistent with the superconducting gap measured by ARPES.
Place, publisher, year, edition, pages
Nature Publishing Group, 2016. Vol. 6, 31352
Underdoped Bi2212, Bi2sr2cacu2o8+Delta, States
IdentifiersURN: urn:nbn:se:kth:diva-192398DOI: 10.1038/srep31352ISI: 000381183600001PubMedID: 27511315ScopusID: 2-s2.0-84982135411OAI: oai:DiVA.org:kth-192398DiVA: diva2:970723
QC 201609142016-09-142016-09-122016-09-14Bibliographically approved