title: Holographic quantum liquid.
abstract: Quantum liquids are characterized by the distinctive properties such as the low-temperature behavior of heat capacity and the spectrum of low-energy quasiparticle excitations. In particular, at low temperature, Fermi liquids exhibit the zero sound, predicted by Landau in 1957 and subsequently observed in liquid He-3. In this Letter, we ask whether such characteristic behavior is present in theories with a holographically dual description. We consider a class of gauge theories with fundamental matter fields whose holographic dual in the appropriate limit is given in terms of the Dirac-Born-Infeld action in anti-de Sitter space. We find that these systems also exhibit a sound mode at zero temperature despite having a non-Fermi-liquid behavior of the specific heat. These properties suggest that holography identifies a new type of quantum liquid which potentially could be experimentally realized in strongly correlated systems.
authors.affiliation: Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA.
authors.forename: A
authors.initials: A
authors.lastname: Karch
authors.forename: D T
authors.initials: DT
authors.lastname: Son
authors.forename: A O
authors.initials: AO
authors.lastname: Starinets