title: Probing the Pairing Interaction and Multiple Bardasis-Schrieffer Modes Using Raman Spectroscopy.
abstract: In unconventional superconductors, understanding the form of the pairing interaction is the primary goal. In this regard, Raman spectroscopy is a very useful tool, as it identifies the ground state and also the subleading pairing channels by probing collective modes. Here, we propose a general theory for a multiband Raman response and identify new features in the spectrum that can provide a robust test for a pairing theory. We identify multiple Bardasis-Schrieffer type collective modes and connect the weights of these modes to the subleading gap structures within a microscopic pairing theory. While our conclusions are completely general, we apply our approach to interpret the specific case of B_{1g} Raman scattering in hole-doped BaFe_{2}As_{2}.
authors.affiliation: Department of Physics, University of Florida, Gainesville, Florida 32611.
authors.forename: S
authors.initials: S
authors.lastname: Maiti
authors.affiliation: Center for Nanophase Materials Sciences and Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6494, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Maier
authors.affiliation: Walther Meissner Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany.|Fakultät für Physik E23, Technische Universität München, 85748 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Böhm
authors.affiliation: Walther Meissner Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Hackl
authors.affiliation: Department of Physics, University of Florida, Gainesville, Florida 32611.
authors.forename: P J
authors.initials: PJ
authors.lastname: Hirschfeld