1,662 research outputs found
Supersymmetric D3/D7 for holographic flavors on curved space
We derive a new class of supersymmetric D3/D7 brane configurations, which
allow to holographically describe N=4 SYM coupled to massive N=2 flavor degrees
of freedom on spaces of constant curvature. We systematically solve the
-symmetry condition for D7-brane embeddings into AdS-sliced
AdSS, and find supersymmetric embeddings in a simple closed form.
Up to a critical mass, these embeddings come in surprisingly diverse families,
and we present a first study of their (holographic) phenomenology. We carry out
the holographic renormalization, compute the one-point functions and attempt a
field-theoretic interpretation of the different families. To complete the
catalog of supersymmetric D3/D7 configurations, we construct analogous
embeddings for flavored N=4 SYM on S and dS.Comment: 37 pages, 9 figure
Flavored N=4 SYM -- a highly entangled quantum liquid
We study N=4 SYM theory coupled to fundamental N=2 hypermultiplets in a state
of finite charge density. The setup can be described holographically as a
configuration of D3 and D7 branes with a non-trivial worldvolume gauge field on
the D7. The phase has been identified as a new form of quantum liquid, where
certain properties are those of a Fermi liquid while others are clearly
distinct. We focus on the entanglement among the flavors, as quantified by the
entanglement entropy. The expectation for a Fermi liquid would be a logarithmic
enhancement of the area law, but we find a more drastic enhancement instead.
The leading contributions are volume terms with a non-trivial shape dependence,
signaling extensive entanglement among the flavors. At finite temperature these
correlations are confined to a region of size given by the inverse temperature.Comment: 16 pages, 2 figures; published version, references adde
On the sign of the dilaton in the soft wall models
We elaborate on the existence of a spurious massless scalar mode in the
vector channel of soft-wall models with incorrectly chosen sign of the
exponential profile defining the wall. We re-iterate the point made in our
earlier paper and demonstrate that the presence of the mode is robust,
depending only on the infra-red asymptotics of the wall. We also re-emphasize
that desired confinement properties can be realized with the correct sign
choice.Comment: 10 page
Chiral Transition of N=4 Super Yang-Mills with Flavor on a 3-Sphere
We use the AdS/CFT correspondence to perform a numerical study of a phase
transition in strongly-coupled large-Nc N = 4 Super-Yang-Mills theory on a
3-sphere coupled to a finite number Nf of massive N = 2 hypermultiplets in the
fundamental representation of the gauge group. The gravity dual system is a
number Nf of probe D7-branes embedded in AdS_5 x S^5. We draw the phase diagram
for this theory in the plane of hypermultiplet mass versus temperature and
identify for temperatures above the Hawking-Page deconfinement temperature a
first-order phase transition line across which the chiral condensate jumps
discontinuously.Comment: 23 pages, 15 figures, minor corrections, reference added, nine
figures improved, no change in results or conclusions; expanded discussion of
fixing finite counterterms in section 3.3, figures updated, no changes to
conclusion
Polarization-sensitive absorption of THz radiation by interacting electrons in chirally stacked multilayer graphene
We show that opacity of a clean multilayer graphene flake depends on the
helicity of the circular polarized electromagnetic radiation. The effect can be
understood in terms of the pseudospin selection rules for the interband optical
transitions in the presence of exchange electron-electron interactions which
alter the pseudospin texture in momentum space. The interactions described
within a semi-analytical Hartree--Fock approach lead to the formation of the
topologically different broken--symmetry states characterized by Chern numbers
and zero-field anomalous Hall conductivities.Comment: 6 pages, final versio
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