Quasiparticle interference and symmetry of superconducting order parameter in strongly electron-doped iron-based superconductors
- Motivated by recent experimental reports of significant spin–orbit coupling (SOC) and a sign-changing order-parameter in the \(Li_{1−x}\)Fe\(_{x}(OHFe)1−y Zn_{y}\) Se superconductor with only electron pockets present, we study the possible Cooper-pairing symmetries and their quasiparticle interference (QPI) signatures. We find that each of the resulting states—\(\it s\)-wave, \(\it d\)-wave and helical \(\it p\)-wave—can have a fully gapped density of states consistent with angle-resolved photoemission spectroscopy experiments and, due to SOC, are a mixture of spin singlet and triplet components leading to intra- and inter-band features in the QPI signal. Analyzing predicted QPI patterns we find that only the spin-triplet dominated even parity \(A_{1g}\) (\(\it s\)-wave) and \(B_{2g}\) (\(\it d\)-wave) pairing states are consistent with the experimental data. Additionally, we show that these states can indeed be realized in a microscopic model with atomic-like interactions and study their possible signatures in spin-resolved STM experiments.
| Author: | Jakob BökerGND, Pavel VolkovORCiDGND, Peter J. HirschfeldGND, Ilya EreminORCiDGND |
|---|---|
| URN: | urn:nbn:de:hbz:294-73076 |
| DOI: | https://doi.org/10.1088/1367-2630/ab2a82 |
| Publisher: | IOP Publishing Ltd |
| Place of publication: | Bristol |
| Document Type: | Article |
| Language: | English |
| Date of Publication (online): | 2020/07/09 |
| Date of first Publication: | 2019/08/09 |
| Publishing Institution: | Ruhr-Universität Bochum, Universitätsbibliothek |
| Tag: | Open Access Fonds iron-based systems, scanning tunneling spectroscopy; phase sensitive probes; spin–orbit coupling; superconducting order parameter; unconventional superconductivity |
| Volume: | 21 |
| Issue: | Artikel 083021 |
| First Page: | 083021-1 |
| Last Page: | 083021-18 |
| Note: | Article Processing Charge funded by the Deutsche Forschungsgemeinschaft (DFG) and the Open Access Publication Fund of Ruhr-Universität Bochum. |
| Institutes/Facilities: | Institut für Theoretische Physik III, Theoretische Festkörperphysik |
| Dewey Decimal Classification: | Naturwissenschaften und Mathematik / Physik |
| open_access (DINI-Set): | open_access |
| Licence (English): |  Creative Commons - CC BY 3.0 Unported - Attribution 3.0 Unported |
