13 research outputs found
Exact Gravity Dual of a Gapless Superconductor
A model of an exact gravity dual of a gapless superconductor is presented in
which the condensate is provided by a charged scalar field coupled to a bulk
black hole of hyperbolic horizon in asymptotically AdS spacetime. Below a
critical temperature, the black hole acquires its hair through a phase
transition while an electromagnetic perturbation of the background Maxwell
field determines the conductivity of the boundary theory.Comment: 21 pages, 8 figures, a section on the stability of the MTZ black hole
is added, references are added, version to be published in JHE
A Rapid Screening Psychometric Test
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66666/2/10.1177_000992286900800506.pd
Antiferromagnetic Zigzag Spin Chain in Magnetic Fields at Finite Temperatures
We study thermodynamic behaviors of the antiferromagnetic zigzag spin chain
in magnetic fields, using the density-matrix renormalization group method for
the quantum transfer matrix. We focus on the thermodynamics of the system near
the critical fields in the ground-state magnetization process(- curve):
the saturation field, the lower critical field associated with excitation gap,
and the field at the middle-field cusp singularity. We calculate magnetization,
susceptibility and specific heat of the zigzag chain in magnetic fields at
finite temperatures, and then discuss how the calculated quantities reflect the
low-lying excitations of the system related with the critical behaviors in the
- curve.Comment: accepted for publication in Physical Review
A Review of Magnetic Phenomena in Probe-Brane Holographic Matter
Gauge/gravity duality is a useful and efficient tool for addressing and
studying questions related to strongly interacting systems described by a gauge
theory. In this manuscript we will review a number of interesting phenomena
that occur in such systems when a background magnetic field is turned on.
Specifically, we will discuss holographic models for systems that include
matter fields in the fundamental representation of the gauge group, which are
incorporated by adding probe branes into the gravitational background dual to
the gauge theory. We include three models in this review: the D3-D7 and D4-D8
models, that describe four-dimensional systems, and the D3-D7' model, that
describes three-dimensional fermions interacting with a four-dimensional gauge
field.Comment: 35 pages, 27 figures, to appear in Lect. Notes Phys. "Strongly
interacting matter in magnetic fields" (Springer), edited by D. Kharzeev, K.
Landsteiner, A. Schmitt, H.-U. Yee; references adde