Holographic Metals and Insulators with Helical Symmetry

TL;DR

This paper constructs holographic models with helical symmetry to explore various metallic and insulating phases, analyzing their electrical conductivities and the effects of translation symmetry breaking.

Contribution

It introduces new homogeneous, zero-temperature solutions with Bianchi VII geometry in Einstein-Maxwell-Dilaton theory, revealing diverse anisotropic phases and their conductive properties.

Findings

Identified insulating and conducting phases with helical symmetry.

Computed frequency and temperature dependence of conductivities.

Showed conduction mechanisms include dissipation and quantum critical currents.

Abstract

Homogeneous, zero temperature scaling solutions with Bianchi VII spatial geometry are constructed in Einstein-Maxwell-Dilaton theory. They correspond to quantum critical saddle points with helical symmetry at finite density. Assuming $AdS_{5}$ UV asymptotics, the small frequency/(temperature) dependence of the AC/(DC) electric conductivity along the director of the helix are computed. A large class of insulating and conducting anisotropic phases is found, as well as isotropic, metallic phases. Conduction can be dominated by dissipation due to weak breaking of translation symmetry or by a quantum critical current.