7,174 research outputs found
Abelian and non-Abelian statistics in the coherent state representation
We further develop an approach to identify the braiding statistics associated
to a given fractional quantum Hall state through adiabatic transport of
quasiparticles. This approach is based on the notion of adiabatic continuity
between quantum Hall states on the torus and simple product states---or
"patterns"---in the thin torus limit, together with a suitable coherent state
Ansatz for localized quasiholes that respects the modular invariance of the
torus. We give a refined and unified account of the application of this method
to the Laughlin and Moore-Read states, which may serve as a pedagogical
introduction to the nuts and bolts of this technique. Our main result is that
the approach is also applicable---without further assumptions---to more
complicated non-Abelian states. We demonstrate this in great detail for the
level Read-Rezayi state at filling factor . These results may
serve as an independent check of other techniques, where the statistics are
inferred from conformal block monodromies. Our approach has the benefit of
giving rise to intuitive pictures representing the transformation of
topological sectors during braiding, and allows for a self-consistent
derivation of non-Abelian statistics without heavy mathematical machinery.Comment: 38 pages, 11 figures, REVTeX 4-1; grammar and typo fixes, published
versio
Momentum resolved tunneling into the Pfaffian and anti-Pfaffian edges
We calculate the electron spectral functions at the edges of the Moore-Read
Pfaffian and anti-Pfaffian fractional quantum Hall states, in the clean limit.
We show that their qualitative differences can be probed using momentum
resolved tunneling, thus providing a method to unambiguously distinguish which
one is realized in the fractional quantum Hall state observed at filling factor
. We further argue that edge reconstruction, which may be less
important in the first excited Landau level (LL) than in the lowest LL, can
also be detected this way if present.Comment: published versio
Domain wall type defects as anyons in phase space
We discuss how the braiding properties of Laughlin quasi-particles in quantum
Hall states can be understood within a one-dimensional formalism we proposed
earlier. In this formalism the two-dimensional space of the Hall liquid is
identified with the phase space of a one-dimensional lattice system, and
localized Laughlin quasi-holes can be understood as coherent states of lattice
solitons. The formalism makes comparatively little use of the detailed
structure of Laughlin wavefunctions, and may offer ways to be generalized to
non-abelian states.Comment: published versio
Bounds for low-energy spectral properties of center-of-mass conserving positive two-body interactions
We study the low-energy spectral properties of positive center-of-mass
conserving two-body Hamiltonians as they arise in models of fractional quantum
Hall states. Starting from the observation that positive many-body Hamiltonians
must have ground-state energies that increase monotonously in particle number,
we explore what general additional constraints can be obtained for two-body
interactions with "center-of-mass conservation" symmetry, both in the presence
and absence of particle-hole symmetry. We find general bounds that constrain
the evolution of the ground-state energy with particle number, and in
particular, constrain the chemical potential at . Special attention is
given to Hamiltonians with zero modes, in which case similar bounds on the
first excited state are also obtained, using a duality property. In this case,
in particular, an upper bound on the charge gap is also obtained. We further
comment on center of mass and relative decomposition in disk geometry within
the framework of second quantization.Comment: 8 pages, published versio
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