Holographic description of strongly coupled nodal-line semimetals

Abstract

Nodal-line semimetals contain a line of Dirac nodes in their band structure, where the conductance band and the valence band touch. Electrons in the vicinity of these nodal lines should be described by strongly coupled quantum field theories, since in those areas we are dealing with a long-range Coulomb interaction. We apply the AdS/CFT correspondence to describe such a material. In this procedure, we map a (3+1)-dimensional strongly coupled conformal field theory to a (4+1)-dimensional weakly coupled anti-de Sitter space. This procedure allows us to predict the spectral function of a nodal-line semimetal, which is measurable in experiments. We find that the strong coupling splits the nodal line into infinitely many nodal lines. When we use semiholography to couple the holographic Green's function to the noninteracting Green's function, we find a spectral function which obeys the ARPES sum rule.