title: Evidence of a pseudogap driven by competing orders of multi-band origin in the ferromagnetic superconductor Sr0.5Ce0.5FBiS2.
abstract: From temperature and magnetic field dependent point-contact spectroscopy on the ferromagnetic superconductor Sr0.5Ce0.5FBiS2 (bulk superconducting [Formula: see text] K) we observe (a) a pseudogap in the normal state that sustains to a remarkably high temperature of 40 K and (b) two-fold enhancement of T c upto 5 K in the point-contact geometry. In addition, Andreev reflection spectroscopy reveals a superconducting gap of 6 meV for certain point-contacts suggesting that the mean field T c of this system could be approximately 40 K, the onset temperature of pseudo-gap. Our results suggest that quantum fluctuations originating from other competing orders in Sr0.5Ce0.5FBiS2 forbid a global phase coherence at high temperatures thereby suppressing T c. Apart from the known ordering to a ferromagnetic state, our first-principles calculations reveal nesting of a multi-band Fermi surface and a significant electron-phonon coupling that could result in charge density wave-like instabilities.
authors.affiliation: Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S. A. S. Nagar, Manauli, PO 140306, India.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Aslam
authors.forename: Arpita
authors.initials: A
authors.lastname: Paul
authors.forename: Gohil S
authors.initials: GS
authors.lastname: Thakur
authors.forename: Sirshendu
authors.initials: S
authors.lastname: Gayen
authors.forename: Ritesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Avtar
authors.initials: A
authors.lastname: Singh
authors.forename: Shekhar
authors.initials: S
authors.lastname: Das
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Ganguli
authors.forename: Umesh V
authors.initials: UV
authors.lastname: Waghmare
authors.forename: Goutam
authors.initials: G
authors.lastname: Sheet