Triplet superconductivity through quadrupolar exciton exchange in PrOs4Sb12

✍ Scribed by P. Thalmeier

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 111 KB
• Volume: 378-380
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2006.01.504

✦ Synopsis

Superconducting pair formation in heavy fermion (HF) compounds is usually attributed to the exchange of over-damped bosonic spin fluctuation modes in the itinerant quasiparticle system. A different mechanism based on the exchange of propagating CEF excitations, i.e., magnetic excitons has previously been identified for UPd 2 Al 3 [Sato, et al., Nature 410 (2001) 340; McHale, et al., Phys. Rev. B 70 (2004) 014513]. We propose a similar model for the tetrahedral (T h ) HF superconductor PrOs 4 Sb 12 . There low energy singlet-triplet CEF excitations exist which disperse into quadrupolar exciton bands as observed in inelastic neutron scattering (INS). Virtual exchange of these collective modes due to aspherical Coulomb scattering leads to Cooper pair formation. Calculations of the effective pairing interactions in non-retarded weak coupling approximation for the irreducible T h channels are presented. The triplet T u symmetry is favored for the gap function.