1. Electronic Structure of Electron-doped Sm1.86Ce0.14CuO4: Strong 'Pseudo-Gap' Effects, Nodeless Gap and Signatures of Short Range Order
- Author
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Park, S. R., Roh, Y. S., Yoon, Y. K., Leem, C. S., Kim, J. H., Kim, B. J., Koh, H., Eisaki, H., Armitage, N. P., and Kim, C.
- Subjects
Superconductivity (cond-mat.supr-con) ,Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,Condensed Matter - Superconductivity ,Condensed Matter::Superconductivity ,FOS: Physical sciences ,Condensed Matter::Strongly Correlated Electrons - Abstract
Angle resolved photoemission (ARPES) data from the electron doped cuprate superconductor Sm$_{1.86}$Ce$_{0.14}$CuO$_4$ shows a much stronger pseudo-gap or "hot-spot" effect than that observed in other optimally doped $n$-type cuprates. Importantly, these effects are strong enough to drive the zone-diagonal states below the chemical potential, implying that d-wave superconductivity in this compound would be of a novel "nodeless" gap variety. The gross features of the Fermi surface topology and low energy electronic structure are found to be well described by reconstruction of bands by a $\sqrt{2}\times\sqrt{2}$ order. Comparison of the ARPES and optical data from the $same$ sample shows that the pseudo-gap energy observed in optical data is consistent with the inter-band transition energy of the model, allowing us to have a unified picture of pseudo-gap effects. However, the high energy electronic structure is found to be inconsistent with such a scenario. We show that a number of these model inconsistencies can be resolved by considering a short range ordering or inhomogeneous state., Comment: 5 pages, 4 figures
- Published
- 2006
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