Nodal-line pairing with 1D-3D coupled Fermi surfaces: a model motivated by Cr-based superconductors

Abstract

Motivated by the recent discovery of a new family of Chromium based superconductors, we consider a two-band model, where a band of electrons dispersing only in one direction interacts with a band of electrons dispersing in all three directions. Strong $2k_f$ density fluctuations in the one-dimensional band induces attractive interactions between the three-dimensional electrons, which, in turn makes the system superconducting. Solving the associated Eliashberg equations, we obtain a gap function which is peaked at the "poles" of the three-dimensional Fermi sphere, and decreases towards the "equator". When strong enough local repulsion is included, the gap actually changes sign around the "equator" and nodal rings are formed. These nodal rings manifest themselves in several experimentally observable quantities, some of which resemble unconventional observations in the newly discovered superconductors which motivated this work.

arXiv comment6 pages. 3 figures

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Cited by in corpus (4)

• Multiband one-dimensional electronic structure and spectroscopic signature of Tomonoga-Luttinger liquid behavior in K${}_2$Cr${}_3$As${}_3$
• Peculiar properties of Cr${}_3$As${}_3$-chain-based superconductors
• Multiband superconductivity and possible nodal gap in RbCr${}_3$As${}_3$ revealed by Andreev reflection and single-particle tunneling measurements
• The upper critical field and its anisotropy in RbCr${}_3$As${}_3$