s+is superconductivity with incipient bands: doping dependence and STM signatures
| Autor: | Konstantin B. Efetov, Jakob Böker, Ilya Eremin, Pavel A. Volkov |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
Superconductivity Condensed matter physics Strongly Correlated Electrons (cond-mat.str-el) Condensed Matter - Superconductivity Doping FOS: Physical sciences Fermi energy 02 engineering and technology Electron 021001 nanoscience & nanotechnology 01 natural sciences Symmetry (physics) law.invention Renormalization Superconductivity (cond-mat.supr-con) Condensed Matter - Strongly Correlated Electrons law Condensed Matter::Superconductivity 0103 physical sciences Condensed Matter::Strongly Correlated Electrons Scanning tunneling microscope 010306 general physics 0210 nano-technology Fermi Gamma-ray Space Telescope |
| DOI: | 10.48550/arxiv.1704.08185 |
| Popis: | Motivated by the recent observations of small Fermi energies and comparatively large superconducting gaps, present also on bands not crossing the Fermi energy (incipient bands) in iron-based superconductors, we analyse the doping evolution of superconductivity in a four-band model across the Lifshitz transition including BCS-BEC crossover effects on the shallow bands. Similar to the BCS case we find that with hole doping the phase difference between superconducting order parameters of the hole bands changes from $0$ to $\pi$ through an intermediate $s+is$ state breaking time-reversal symmetry. The transition however occurs in the region where electron bands are incipient and chemical potential renormalization in the superconducting state leads to a significant broadening of the $s+is$ region. We further present the qualitative features of the $s+is$ state that can be observed in scanning tunnelling microscopy (STM) experiments also taking incipient bands into account. Comment: 18 pages, 9 figures |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|