Low-temperature specific heat of the heavy-fermion superconductor PrOs4Sb12.
We report the magnetic field dependence of the specific-heat C of single crystals of the first Pr-based heavy-fermion superconductor Pr(Os4Sb12. The variation of C at low temperature and the magnetic phase diagram inferred from C, the resistivity and magnetization provide compelling evidence of a doublet ground state. Two distinct superconducting anomalies in C indicate an unconventional superconducting state, where the splitting may arise from a weak lifting of the ground state degeneracy. In combination this identifies Pr(Os4Sb12 as a strong contender for quadrupolar pairing, i.e., superconductivity that is neither electron-phonon nor magnetically mediated.
Vollmer
R
R
Physikalisches Institut, Universität Karlsruhe, Wolfgang-Gaede-Strasse 1, Germany.
Faisst
A
A
Pfleiderer
C
C
V  Löhneysen
H
H
Bauer
E D
ED
Ho
P-C
PC
Zapf
V
V
Maple
M B
MB