Regensburg 2019 – wissenschaftliches Programm
TT 15.12: Vortrag
Montag, 1. April 2019, 18:15–18:30, H23
Quasiparticle Interference and Symmetry of Superconducting Order Parameter in Strongly Electron-Doped Iron-based Superconductors — •Jakob Böker1, Pavel Volkov2, Peter Hirschfeld3, and Ilya Eremin1 — 1Institut für Theoretische Physik III, Ruhr-Universität Bochum, D-44780 Bochum, Germany — 2Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey, 08854, USA — 3Department of Physics, University of Florida, Gainesville, Florida32611, USA
Motivated by recent experimental reports of significant spin-orbit coupling (SOC) and a sign-changing order-parameter in the Li1−xFex(OHFe)1−yZnySe superconductor with only electron Fermi surface present, we study the possible Cooper-pairing symmetries and their quasiparticle interference (QPI) signatures. We find that each of the resulting states - s-wave, d-wave and helical p-wave - can have a fully gapped density of states (DOS) consistent with angle-resolved photoemission experiments (ARPES) experiments and, due to spin-orbit coupling, 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 s- and d-wave pairing states with a dominant even parity triplet component can fit the experimental data with two dominant peaks in the DOS at energies roughly corresponding to the gap sizes at each pocket. Moreover, we show that pairing states with dominant triplet component may exist and can be identified using spin-resolved STM.