Abstract
Observations of robust superconductivity in some of the iron based superconductors in the vicinity of a Lifshitz point where a spin density wave instability is suppressed as the hole band drops below the Fermi energy raise questions for spin-fluctuation theories. Here we discuss spin-fluctuation pairing for a bilayer Hubbard model, which goes through such a Lifshitz transition. We find s± pairing with a transition temperature that peaks beyond the Lifshitz point and a gap function that has essentially the same magnitude but opposite sign on the incipient hole band as it does on the electron band that has a Fermi surface.
| Original language | English |
|---|---|
| Article number | 32078 |
| Journal | Scientific Reports |
| Volume | 6 |
| DOIs | |
| State | Published - Aug 26 2016 |
Funding
Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy. DJS and TAM acknowledge the support of the Center for Nanophase Materials Sciences, a US DOE Office of Science User Facility. We acknowledge the Valinor cluster for computational resources. We thank A. Linscheid, S. Maiti, P. Hirschfeld for useful discussion.