Interplay between superconducting and magnetic fluctuations in the doped 2D Hubbard model*

The importance of antiferromagnetism for d-wave type superconductivity has already been established within various theoretical methods [1]. In this work we focus on the doped regime, where the magnetic fluctuations become incommensurate [2]. The solution of the Hubbard model by parquet equations gives us the unique opportunity to treat fluctuations in all channels on equal footing. Using the victory parquet equations solver [3] we compute two-particle quantities in the 2D Hubbard model on square lattice in the parquet (PA) and dynamical vertex (DΓA) approximations [4][5]. In the parquet flavour of DΓA, the fully irreducible vertex is assumed to be local and it is obtained from dynamical mean-field theory (DMFT). The analysis of the particle-particle vertex as well as of the leading eigenvalues of the Bethe-Salpeter equations allow us to identify the dominant fluctuations and the symmetry of the pairing.

[1] D. J. Scalapino, Rev. Mod. Phys. 84, (2012)
[2] A. Kauch, F. Hörbinger, G. Li and K. Held, in preparation
[3] G. Li, A. Kauch, P. Pudleiner, and K. Held, arXiv:1708.07457, submitted to Comput. Phys. Commun.
[4] K. Held, Adv. Phys. 56, 829 (2007)
[5] G. Rohringer et al., Rev. Mod. Phys., 90, 025003 (2018)