Interaction-driven localization in holography

Donos, Aristomenis; Hartnoll, Sean A.

Abstract

Interaction-driven charge localization across a quantum phase transition involves a fundamental rearrangement of the low-energy degrees of freedom. This fact challenges weakly interacting quasiparticle descriptions of the physics. The canonical example of such localization is the Mott transition. Here, we present a localization mechanism distinct from ‘Mottness’, which employs strong interactions in an essential way. Our mechanism allows anisotropic localization: phases can arise that are insulating in some directions and metallic in others. The central observation is that localization occurs if an operator that breaks translation invariance, a ‘generalized Umklapp’ operator, becomes relevant in the effective low-energy theory. This does not occur at weak coupling. We realize such localization in a strongly interacting theory described by means of the holographic correspondence. Our model captures key features of metal–insulator transitions including major spectral weight transfer and bad (incoherent) metallic behaviour in the vicinity of the transition. The localized phase has a power law gap in the optical conductivity.

Citation

Donos, A., & Hartnoll, S. A. (2013). Interaction-driven localization in holography. Nature Physics, 9(10), 649-655. https://doi.org/10.1038/nphys2701

• Journal Article Type: Article
• Publication Date: 2013-10
• Deposit Date: Dec 10, 2014
• Journal: Nature Physics
• Print ISSN: 1745-2473
• Electronic ISSN: 1745-2481
• Publisher: Nature Research
• Volume: 9
• Issue: 10
• Pages: 649-655
• DOI: https://doi.org/10.1038/nphys2701
• Public URL: https://durham-repository.worktribe.com/output/1440339