31,336 research outputs found
Effective Theories for 2+1 Dimensional Non-Abelian Topological Spin Liquids
In this work we propose an effective low-energy theory for a large class of
2+1 dimensional non-Abelian topological spin liquids whose edge states are
conformal degrees of freedom with central charges corresponding to the coset
structure . For particular values of
it furnishes the series for unitary minimal and superconformal models.
These gapped phases were recently suggested to be obtained from an array of
one-dimensional coupled quantum wires. In doing so we provide an explicit
relationship between two distinct approaches: quantum wires and Chern-Simons
bulk theory. We firstly make a direct connection between the interacting
quantum wires and the corresponding conformal field theory at the edges, which
turns out to be given in terms of chiral gauged WZW models. Relying on the
bulk-edge correspondence we are able to construct the underlying non-Abelian
Chern-Simons effective field theory.Comment: 41 pages, 5 figures, typos corrected, references added, published
versio
Stability of a two-sublattice spin-glass model
We study the stability of the replica-symmetric solution of a two-sublattice
infinite-range spin-glass model, which can describe the transition from
antiferromagnetic to spin glass state. The eigenvalues associated with
replica-symmetric perturbations are in general complex. The natural
generalization of the usual stability condition is to require the real part of
these eigenvalues to be positive. The necessary and sufficient conditions for
all the roots of the secular equation to have positive real parts is given by
the Hurwitz criterion. The generalized stability condition allows a consistent
analysis of the phase diagram within the replica-symmetric approximation.Comment: 21 pages, 5 figure
Statistical Theory of Breakup Reactions
We propose alternatives to coupled-channels calculations with loosely-bound
exotic nuclei (CDCC), based on the the random matrix (RMT) and the optical
background (OPM) models for the statistical theory of nuclear reactions. The
coupled channels equations are divided into two sets. The first set, described
by the CDCC, and the other set treated with RMT. The resulting theory is a
Statistical CDCC (CDCC), able in principle to take into account many pseudo
channels.Comment: 15 pages, 4 figures. Contribution to: "4th International Workshop on
Compound-Nuclear Reactions and Related Topics (CNR*13)", October 7-11, 2013,
Maresias, Brazi
Diffusion in Fluctuating Media: The Resonant Activation Problem
We present a one-dimensional model for diffusion in a fluctuating lattice;
that is a lattice which can be in two or more states. Transitions between the
lattice states are induced by a combination of two processes: one periodic
deterministic and the other stochastic. We study the dynamics of a system of
particles moving in that medium, and characterize the problem from different
points of view: mean first passage time (MFPT), probability of return to a
given site (), and the total length displacement or number of visited
lattice sites (). We observe a double {\it resonant activation}-like
phenomenon when we plot the MFPT and as functions of the intensity of
the transition rate stochastic component.Comment: RevTex, 15 pgs, 8 figures, submitted to Eur.Phys.J.
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