2018/12/03 by Avraham Klein, Klein, Avraham, Yi-Ming Wu +3
Physics and Astronomy · #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1812.00521
arxiv created 2018/12/03 · arxiv updated 2018/12/04
Superconductivity in many strongly correlated materials appears in proximity to a density-wave or nematic order and is believed to be mediated by quantum-critical (QC) fluctuations of the corresponding order parameter. We argue that fingerprints of QC pairing can be extracted from the angular dependence of the gap Δ(θ). We consider pairing by QC nematic fluctuations and show that there exist multiple pairing instabilities within the same symmetry (s-wave in our case), with closely spaced transition temperatures Tc,n. The corresponding Δn (θ) change sign 8n times along the FS. Only the solution with the highest Tc,0 =Tc develops, but other gap components are induced below Tc and get resonantly enhanced below Tc,n. This gives rise to strong variation of the angular dependence of the gap below Tc. The effect gets much weaker away from a quantum-critical point.