2018/04/30 by Vasilii Vadimov, V. L. Vadimov, М. А. Силаев +1
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Iron-based superconductors research #Magnetic field #Muon spin spectroscopy #Pairing #Physics #Quantum mechanics #Rare-earth and actinide compounds #Superconductivity #Symmetry breaking #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.98.104504
published as Phys. Rev. B 98, 104504 (2018)
openalex created_date 2018/05/07 · arxiv created 2018/08/20 · openalex publication_date 2018/09/07 · arxiv updated 2018/09/11 · openalex updated_date 2026/08/05
We show that multiband superconductors with broken time-reversal symmetry can produce spontaneous currents and magnetic fields in response to the local variations of pairing constants. Considering the iron pnictide superconductor Ba_1\ensuremath-xKxFe2As2 as an example we demonstrate that both the point-group symmetric s+is state and the C4-symmetry-breaking s+id states produce, in general, the same magnitudes of spontaneous magnetic fields. In the s+is state these fields are polarized mainly on an ab crystal plane, whereas in the s+id state their ab-plane and c-axis components are of the same order. The same is true for the random magnetic fields which are produced by the order parameter fluctuations near the critical point of the time-reversal symmetry-breaking phase transition. Our findings can be used as a direct test of the s+is/s+id dichotomy and the additional discrete symmetry-breaking phase transitions with the help of muon spin-relaxation experiments.