97 research outputs found
Under The Dome: Doped holographic superconductors with broken translational symmetry
We comment on a simple way to accommodate translational symmetry breaking
into the recently proposed holographic model which features a superconducting
dome-shaped region on the temperature-doping phase diagram.Comment: 14 pages, 6 figure
Phases of holographic superconductors with broken translational symmetry
We consider holographic superconductors in a broad class of massive gravity
backgrounds. These theories provide a holographic description of a
superconductor with broken translational symmetry. Such models exhibit a rich
phase structure: depending on the values of the temperature and the disorder
strength the boundary system can be in superconducting, normal metallic or
normal pseudoinsulating phases. Furthermore the system supports interesting
collective excitation of the charge carriers, which appears in the normal
phase, persists in the superconducting phase, but eventually gets destroyed by
the superconducting condensate. We also show the possibility of building a
phase diagram of a system with the superconducting phase occupying a
dome-shaped region on the temperature-disorder plane.Comment: Minor revisions, interpretation clarified, version published in JHE
How small hydrodynamics can go
Numerous experimental and theoretical results in liquids and plasmas suggest
the presence of a critical momentum at which the shear diffusion mode collides
with a non-hydrodynamic relaxation mode, giving rise to propagating shear
waves. This phenomenon, labelled as "k-gap", could explain the surprising
identification of a low-frequency elastic behaviour in confined liquids. More
recently, a formal study of the perturbative hydrodynamic expansion showed that
critical points in complex space, such as the aforementioned k-gap, determine
the radius of convergence of linear hydrodynamics, its regime of applicability.
In this work, we combine the two new concepts and we study the radius of
convergence of linear hydrodynamics in "real liquids" by using several data
from simulations and experiments. We generically show that the radius of
convergence increases with temperature and it surprisingly decreases with the
electromagnetic interactions coupling. More importantly, for all the systems
considered, we find that such radius is set by the Wigner-Seitz radius, the
characteristic inter-atomic distance of the liquid, which provides a natural
microscopic bound.Comment: v2: matching the published versio
- …