Anomalous s-wave proximity-induced Josephson effects in ${\mathrm{UBe}}_{13}$, ${\mathrm{CeCu}}_2$${\mathrm{Si}}_2$, and ${\mathrm{LaBe}}_{13}$: A new probe of heavy-fermion superconductivity

Anomalous proximity-induced s-wave superconductivity has been observed via the ac Josephson effect and the magnetic field and temperature dependences of the Josephson current in Nb/${\mathrm{CeCu}}_2$ ${\mathrm{Si}}_2$, Nb/${\mathrm{LaBe}}_{13}$, and Nb/${\mathrm{UBe}}_{13}$ junctions. The origin of the proximity-induced Josephson effect and its utility in discovering the pairing type in heavy-fermion metals are discussed.