41 research outputs found
Universality Lost: Relation between quantizations of the Hall conductance and the edge exponents in fractional quantum Hall effect
We note an implication of chiral Luttinger liquid based edge state
description of the fractional quantum Hall effect. By considering several
examples that involve backward moving neutral modes, arising from either
composite fermions with reverse flux attached or edge reconstruction, we show
that non-universality of the edge exponent implies non-universality of the Hall
conductance, as measured in the two-terminal conductance.Comment: 4 pages, published version: added clarification on the issue of
disorde
A Thermodynamic Interpretation of Time for Superstring Rolling Tachyons
Rolling tachyon backgrounds, arising from open strings on unstable branes in
bosonic string theory, can be related to a simple statistical mechanical model
- Coulomb gas of point charges in two dimensions confined to a circle, the
Dyson gas. In this letter we describe a statistical system that is dual to
non-BPS branes in superstring theory. We argue that even though the concept of
time is absent in the statistical dual sitting at equilibrium, the notion of
time can emerge at the large number of particles limit.Comment: 6 pages, 3 figures, v2: reference added, v3: minor clarification,
version to appear in journa
Superconducting Dome from Holography
We find a regime in which a strongly coupled striped superconductor features
a superconducting dome. This regime is signified by i) a modulating chemical
potential that averages to zero, and ii) a superconducting order parameter that
has a scaling dimension larger than 3/2 but less than or equal to 3. We also
find that in this regime, the order parameter exhibits a mild dependence on the
modulation wavelength of the stripe.Comment: 5 pages, 4 figure
Enhancement of Critical Temperature of a Striped Holographic Superconductor
We study the interplay between the stripe order and the superconducting order
in a strongly coupled striped superconductor using gauge/gravity duality. In
particular, we study the effects of inhomogeneity introduced by the stripe
order on the superconducting transition temperature beyond the mean field level
by including the effects of backreaction onto the spacetime geometry in the
dual gravitational picture. We find that inhomogeneity \emph{enhances} the
critical temperature relative to its value for the uniform system.Comment: 8 pages, 7 figure
Two-terminal transport along a proximity induced superconducting quantum Hall edge
We study electric transport along an integer quantum Hall edge where the
proximity effect is induced due to a coupling to a superconductor. Such an edge
exhibits two Majorana-Weyl fermions with different group velocities set by the
induced superconducting pairing. We show that this structure of the spectrum
results in interference fringes that can be observed in both the two-terminal
conductance and shot noise. We develop a complete analytical theory of such
fringes for an arbitrary smooth profile of the induced pairing.Comment: 5+1 pages, 2 figure