Heavy fermion superconductor
Heavy fermion superconductors are a type of unconventional superconductor.
The first heavy fermion superconductor, CeCu2Si2, was discovered by Frank Steglich in 1978.
Since then over 30 heavy fermion superconductors were found (in materials based on Ce, U), with a critical temperature up to 2.3 K (in CeCoIn5).