Heavy fermion superconductors are a type of unconventional superconductor.
The first heavy fermion superconductor, CeCu2Si2, was discovered by Frank Steglich in 1978. [1]
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). [2]
Material | TC (K) | comments | original reference |
---|---|---|---|
CeCu2Si2 | 0.7 | first unconventional superconductor | [1] |
CeCoIn5 | 2.3 | highest TC of all Ce-based heavy fermions | [2] |
CePt3Si | 0.75 | first heavy-fermion superconductor with non-centrosymmetric crystal structure | [3] |
CeIn3 | 0.2 | superconducting only at high pressures | [4] |
UBe13 | 0.85 | p-wave superconductor | [5] |
UPt3 | 0.48 | several distinct superconducting phases | [6] |
URu2Si2 | 1.3 | mysterious 'hidden-order phase' below 17 K | [7] |
UPd2Al3 | 2.0 | antiferromagnetic below 14 K | [8] |
UNi2Al3 | 1.1 | antiferromagnetic below 5 K | [9] |
Heavy Fermion materials are intermetallic compounds, containing rare earth or actinide elements. The f-electrons of these atoms hybridize with the normal conduction electrons leading to quasiparticles with an enhanced effective mass.[ citation needed]
From specific heat measurements (ΔC/C(TC) one knows that the Cooper pairs in the superconducting state are also formed by the heavy quasiparticles. [10] In contrast to normal superconductors it cannot be described by BCS-Theory. Due to the large effective mass, [11] the Fermi velocity is reduced and comparable to the inverse Debye frequency. This leads to the failing of the picture of electrons polarizing the lattice as an attractive force.[ citation needed]
Some heavy fermion superconductors are candidate materials for the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. [12] In particular there has been evidence that CeCoIn5 close to the critical field is in an FFLO state. [13]
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link)
Heavy fermion superconductors are a type of unconventional superconductor.
The first heavy fermion superconductor, CeCu2Si2, was discovered by Frank Steglich in 1978. [1]
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). [2]
Material | TC (K) | comments | original reference |
---|---|---|---|
CeCu2Si2 | 0.7 | first unconventional superconductor | [1] |
CeCoIn5 | 2.3 | highest TC of all Ce-based heavy fermions | [2] |
CePt3Si | 0.75 | first heavy-fermion superconductor with non-centrosymmetric crystal structure | [3] |
CeIn3 | 0.2 | superconducting only at high pressures | [4] |
UBe13 | 0.85 | p-wave superconductor | [5] |
UPt3 | 0.48 | several distinct superconducting phases | [6] |
URu2Si2 | 1.3 | mysterious 'hidden-order phase' below 17 K | [7] |
UPd2Al3 | 2.0 | antiferromagnetic below 14 K | [8] |
UNi2Al3 | 1.1 | antiferromagnetic below 5 K | [9] |
Heavy Fermion materials are intermetallic compounds, containing rare earth or actinide elements. The f-electrons of these atoms hybridize with the normal conduction electrons leading to quasiparticles with an enhanced effective mass.[ citation needed]
From specific heat measurements (ΔC/C(TC) one knows that the Cooper pairs in the superconducting state are also formed by the heavy quasiparticles. [10] In contrast to normal superconductors it cannot be described by BCS-Theory. Due to the large effective mass, [11] the Fermi velocity is reduced and comparable to the inverse Debye frequency. This leads to the failing of the picture of electrons polarizing the lattice as an attractive force.[ citation needed]
Some heavy fermion superconductors are candidate materials for the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. [12] In particular there has been evidence that CeCoIn5 close to the critical field is in an FFLO state. [13]
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link)