Superconductivity near a Quantum-Critical Point: The Special Role of the First Matsubara Frequency. Academic Article uri icon

abstract

  • Near a quantum-critical point in a metal strong fermion-fermion interaction mediated by a soft collective boson gives rise to incoherent, non-Fermi liquid behavior. It also often gives rise to superconductivity which masks the non-Fermi liquid behavior. We analyze the interplay between the tendency to pairing and fermionic incoherence for a set of quantum-critical models with effective dynamical interaction between low-energy fermions. We argue that superconducting T_{c} is nonzero even for strong incoherence and/or weak interaction due to the fact that the self-energy from dynamic critical fluctuations vanishes for the two lowest fermionic Matsubara frequencies ω_{m}=±πT. We obtain the analytic formula for T_{c}, which reproduces well earlier numerical results for the electron-phonon model at vanishing Debye frequency.

published proceedings

  • Phys Rev Lett

altmetric score

  • 1.75

author list (cited authors)

  • Wang, Y., Abanov, A., Altshuler, B. L., Yuzbashyan, E. A., & Chubukov, A. V

citation count

  • 45

complete list of authors

  • Wang, Yuxuan||Abanov, Artem||Altshuler, Boris L||Yuzbashyan, Emil A||Chubukov, Andrey V

publication date

  • October 2016