2 research outputs found
Mixed symmetry superconductivity in two-dimensional Fermi liquids
We consider a 2D isotropic Fermi liquid with attraction in both and
channels and examine the possibility of a superconducting state with mixed
and symmetry of the gap function. We show that both in the weak coupling
limit and at strong coupling, a mixed symmetry state is realized in a
certain range of interaction. Phase transitions between the mixed and the pure
symmetry states are second order. We also show that there is no stable mixed
symmetry state at any coupling.Comment: 3 figures attached in uuencoded gzipped file
Chiral d+is superconducting state in the two dimensional t-t' Hubbard model
Applying the recently developed variational approach to Kohn-Luttinger
superconductivity to the t-t' Hubbard model in two dimensions, we have found,
for sizeable next-nearest neighbor hopping, an electron density controlled
quantum phase transition between a d-wave superconducting state close to half
filling and an s-wave superconductor at lower electron density. The transition
occurs via an intermediate time reversal breaking d+is superconducting phase,
which is characterized by nonvanishing chirality and density-current
correlation. Our results suggest the possibility of a bulk time reversal
symmetry breaking state in overdoped cuprates