title: Evidence of electromagnetic absorption by collective modes in the heavy fermion superconductor UBe(13).
abstract: We present results of a microwave surface impedance study of the heavy fermion superconductor UBe(13). We clearly observe an absorption peak whose frequency and temperature dependence scales with the BCS gap function Delta(T). Resonant absorption into a collective mode, with energy approximately proportional to the superconducting gap, is proposed as a possible explanation. Fits to the data provide a simple relation between Delta(T) and the collective mode frequency.
authors.affiliation: Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Feller
authors.forename: C-C
authors.initials: CC
authors.lastname: Tsai
authors.forename: J B
authors.initials: JB
authors.lastname: Ketterson
authors.forename: J L
authors.initials: JL
authors.lastname: Smith
authors.forename: Bimal K
authors.initials: BK
authors.lastname: Sarma