338 research outputs found
Spin texture readout of a Moore-Read topological quantum register
We study the composite Charged Spin Texture (CST) over the Moore-Read quantum
Hall state that arises when a collection of elementary CSTs are moved to the
same location. Following an algebraic approach based on the characteristic pair
correlations of the Moore-Read state, we find that the resulting CST is set by
the fusion sector of the underlying non-Abelian quasiparticles. This phenomenon
provides a novel way to read out the quantum register of a non-Abelian
topologically ordered phase.Comment: 4 pages, 6 figure
Superspace WZW Models and Black Holes
We show how to write an off-shell action for the
supersymmetric WZW model in terms of chiral and twisted chiral
multiplets. We discuss the supersymmetry of this model and exhibit the
superconformal current algebra. Finally, we show that the off-shell
formulation makes it possible to perform a duality transformation, which leads
to a supersymmetric sigma model on a manifold with a black hole type
singularity.Comment: 12 page
One-parameter extension of the Doi-Peliti formalism and relation with orthogonal polynomials
An extension of the Doi-Peliti formalism for stochastic chemical kinetics is
proposed. Using the extension, path-integral expressions consistent with
previous studies are obtained. In addition, the extended formalism is naturally
connected to orthogonal polynomials. We show that two different orthogonal
polynomials, i.e., Charlier polynomials and Hermite polynomials, can be used to
express the Doi-Peliti formalism explicitly.Comment: 10 page
Supersymmetric Reflection Matrices
We briefly review the general structure of integrable particle theories in
1+1 dimensions having N=1 supersymmetry. Examples are specific perturbed
superconformal field theories (of Yang-Lee type) and the N=1 supersymmetric
sine-Gordon theory. We comment on the modifications that are required when the
N=1 supersymmetry algebra contains non-trivial topological charges.Comment: 7 pages, Revtex, 2 figures, talk given at the International Seminar
on Supersymmetry and Quantum Field Theory, dedicated to the memory of
D.V.Volkov, Kharkov (Ukraine), January 5-7, 199
Cooper pairs and exclusion statistics from coupled free-fermion chains
We show how to couple two free-fermion chains so that the excitations consist
of Cooper pairs with zero energy, and free particles obeying (mutual) exclusion
statistics. This behavior is reminiscent of anyonic superconductivity, and of a
ferromagnetic version of the Haldane-Shastry spin chain, although here the
interactions are local. We solve this model using the nested Bethe ansatz, and
find all the eigenstates; the Cooper pairs correspond to exact-string or
``0/0'' solutions of the Bethe equations. We show how the model possesses an
infinite-dimensional symmetry algebra, which is a supersymmetric version of the
Yangian symmetry algebra for the Haldane-Shastry model.Comment: 16 pages. v2: includes explicit expression for super-Yangian
generato
Hard squares with negative activity
We show that the hard-square lattice gas with activity z= -1 has a number of
remarkable properties. We conjecture that all the eigenvalues of the transfer
matrix are roots of unity. They fall into groups (``strings'') evenly spaced
around the unit circle, which have interesting number-theoretic properties. For
example, the partition function on an M by N lattice with periodic boundary
condition is identically 1 when M and N are coprime. We provide evidence for
these conjectures from analytical and numerical arguments.Comment: 8 page
Non-Abelian anyons: when Ising meets Fibonacci
We consider an interface between two non-Abelian quantum Hall states: the
Moore-Read state, supporting anyons of Ising type, and the k=2 NASS
(non-Abelian spin-singlet) state, supporting anyons of Fibonacci type. It is
shown that the interface supports neutral excitations described by a 1+1
dimensional conformal field theory with central charge c=7/10. We discuss
effects of the mismatch of the quantum statistical properties of the
quasi-holes between the two sides, as reflected by the interface theory.Comment: As published in PR
Background gauge invariance in the antifield formalism for theories with open gauge algebras
We show that any BRST invariant quantum action with open or closed gauge
algebra has a corresponding local background gauge invariance. If the BRST
symmetry is anomalous, but the anomaly can be removed in the antifield
formalism, then the effective action possesses a local background gauge
invariance. The presence of antifields (BRST sources) is necessary. As an
example we analyze chiral gravity.Comment: 17pp., Latex, mispelling in my name! corrected, no other change
K-matrices for non-abelian quantum Hall states
Two fundamental aspects of so-called non-abelian quantum Hall states (the
q-pfaffian states and more general) are a (generalized) pairing of the
participating electrons and the non-abelian statistics of the quasi-hole
excitations. In this paper, we show that these two aspects are linked by a
duality relation, which can be made manifest by considering the K-matrices that
describe the exclusion statistics of the fundamental excitations in these
systems.Comment: LaTeX, 12 page
Dual formulation of classical W-algebras
By extending the concept of \mc, I introduce a dual formulation of
(classical) nonlinear extensions of the \vir\ algebra. This dual formulation is
closely related to three dimensional actions which are analogous to a \cs\
action. I present an explicit construction in terms of superfields of the
super \wfour.Comment: (only change is an added reference), 9 pages, USC--92/01
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