title: Unconventional Superconductivity in La(7)Ir(3) Revealed by Muon Spin Relaxation: Introducing a New Family of Noncentrosymmetric Superconductor That Breaks Time-Reversal Symmetry.
abstract: The superconductivity of the noncentrosymmetric compound La(7)Ir(3) is investigated using muon spin rotation and relaxation. Zero-field measurements reveal the presence of spontaneous static or quasistatic magnetic fields below the superconducting transition temperature T(c)=2.25  K-a clear indication that the superconducting state breaks time-reversal symmetry. Furthermore, transverse-field rotation measurements suggest that the superconducting gap is isotropic and that the pairing symmetry of the superconducting electrons is predominantly s wave with an enhanced binding strength. The results indicate that the superconductivity in La(7)Ir(3) may be unconventional and paves the way for further studies of this family of materials.
authors.affiliation: Physics Department, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: J A T
authors.initials: JA
authors.lastname: Barker
authors.affiliation: Department of Physics, Indian Institute of Science Education and Research Bhopal, Bhopal 462066, India.
authors.forename: D
authors.initials: D
authors.lastname: Singh
authors.affiliation: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai 400005, India.
authors.forename: A
authors.initials: A
authors.lastname: Thamizhavel
authors.affiliation: ISIS facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Oxfordshire OX11 0QX, United Kingdom.
authors.forename: A D
authors.initials: AD
authors.lastname: Hillier
authors.affiliation: Physics Department, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: M R
authors.initials: MR
authors.lastname: Lees
authors.affiliation: Physics Department, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: G
authors.initials: G
authors.lastname: Balakrishnan
authors.affiliation: Physics Department, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: D McK
authors.initials: DM
authors.lastname: Paul
authors.affiliation: Department of Physics, Indian Institute of Science Education and Research Bhopal, Bhopal 462066, India.
authors.forename: R P
authors.initials: RP
authors.lastname: Singh