Phenomenological characterisation of semi-holographic non-Fermi liquids

TL;DR

This paper explores semi-holographic models for non-Fermi liquids, revealing generalized Landau-Silin equations and showing that collective excitations can differ significantly from traditional Fermi liquid behavior.

Contribution

It introduces a phenomenological framework for non-Fermi liquids based on semi-holography, extending Landau-Silin theory with fewer parameters and novel collective excitation behaviors.

Findings

Generalized Landau-Silin equations with few parameters

Collective excitations can differ from traditional Fermi liquids

Fermi surface with well-defined quasi-particles can still exhibit non-Fermi liquid behavior

Abstract

We analyse some phenomenological implications of the most general semi-holographic models for non-Fermi liquids that have emerged with inputs from the holographic correspondence. We find generalizations of Landau-Silin equations with few parameters governing thermodynamics, low energy response and collective excitations. We show that even when there is a Fermi surface with well-defined quasi-particle excitations, the collective excitations can behave very differently from Landau's theory.