Pairing in quantum critical systems: Transition temperature, pairing gap, and their ratio Academic Article uri icon


  • 2019 American Physical Society. We compute the ratio of the pairing gap at T=0 and Tc for a set of quantum-critical models in which the pairing interaction is mediated by a gapless boson with local susceptibility ()1/|| (the model). The limit =0+ [()=log||] describes color superconductivity, and models with >0 describe superconductivity in a metal at the onset of charge or spin order. The ratio 2/Tc has been recently computed numerically for 0<<2 within Eliashberg theory and was found to increase with increasing [T.-H. Lee, Phys. Rev. Lett. 121, 187003 (2018)10.1103/PhysRevLett.121.187003]. We argue that the origin of the increase is the divergence of 2/Tc at =3. We obtain an approximate analytical formula for 2/Tc for 3 and show that it agrees well with the numerics. We also consider in detail the opposite limit of small . Here we obtain the explicit expressions for Tc and , including numerical prefactors. We show that these prefactors depend on fermionic self-energy in a rather nontrivial way. The ratio 2/Tc approaches the BCS value 3.53 at 0.

published proceedings

  • Physical Review B

altmetric score

  • 0.25

author list (cited authors)

  • Wu, Y., Abanov, A., & Chubukov, A. V.

citation count

  • 16

complete list of authors

  • Wu, Yi-Ming||Abanov, Artem||Chubukov, Andrey V

publication date

  • January 2019