27,677 research outputs found
Nonuniversal exponents in sandpiles with stochastic particle number transfer
We study fixed density sandpiles in which the number of particles transferred
to a neighbor on relaxing an active site is determined stochastically by a
parameter . Using an argument, the critical density at which an
active-absorbing transition occurs is found exactly. We study the critical
behavior numerically and find that the exponents associated with both static
and time-dependent quantities vary continuously with .Comment: Some parts rewritten, results unchanged. To appear in Europhys. Let
Relevance of inter-composite fermion interaction to the edge Tomonaga-Luttinger liquid
It is shown that Wen's effective theory correctly describes the
Tomonaga-Luttinger liquid at the edge of a system of non-interacting composite
fermions. However, the weak residual interaction between composite fermions
appears to be a relevant perturbation. The filling factor dependence of the
Tomonaga-Luttinger parameter is estimated for interacting composite fermions in
a microscopic approach and satisfactory agreement with experiment is achieved.
It is suggested that the electron field operator may not have a simple
representation in the effective one dimensional theory.Comment: 5 pages; accepted in Phys. Rev. Let
Spatial operator algebra framework for multibody system dynamics
The Spatial Operator Algebra framework for the dynamics of general multibody systems is described. The use of a spatial operator-based methodology permits the formulation of the dynamical equations of motion of multibody systems in a concise and systematic way. The dynamical equations of progressively more complex grid multibody systems are developed in an evolutionary manner beginning with a serial chain system, followed by a tree topology system and finally, systems with arbitrary closed loops. Operator factorizations and identities are used to develop novel recursive algorithms for the forward dynamics of systems with closed loops. Extensions required to deal with flexible elements are also discussed
Creating and manipulating non-Abelian anyons in cold atom systems using auxiliary bosons
The possibility of realizing bosonic fractional quantum Hall effect in
ultra-cold atomic systems suggests a new route to producing and manipulating
anyons, by introducing auxiliary bosons of a different species that capture
quasiholes and thus inherit their non-trivial braiding properties. States with
localized quasiholes at any desired locations can be obtained by annihilating
the auxiliary bosons at those locations. We explore how this method can be used
to generate non-Abelian quasiholes of the Moore-Read Pfaffian state for bosons
at filling factor . We show that a Hamiltonian with an appropriate
three-body interaction can produce two-quasihole states in two distinct fusion
channels of the topological "qubit." Characteristics of these states that are
related to the non-Abelian nature can be probed and verified by a measurement
of the effective relative angular momentum of the auxiliary bosons, which is
directly related to their pair distribution function. Moore-Read states of more
than two quasiholes can also be produced in a similar fashion. We investigate
some issues related to the experimental feasibility of this approach, in
particular, how large the systems should be for a realization of this physics
and to what extent this physics carries over to systems with the more standard
two-body contact interaction.Comment: 16 pages, 6 figure
Reconstructing the electron in a fractionalized quantum fluid
The low energy physics of the fractional Hall liquid is described in terms
quasiparticles that are qualitatively distinct from electrons. We show,
however, that a long-lived electron-like quasiparticle also exists in the
excitation spectrum: the state obtained by the application of an electron
creation operator to a fractional quantum Hall ground state has a non-zero
overlap with a complex, high energy bound state containing an odd number of
composite-fermion quasiparticles. The electron annihilation operator similarly
couples to a bound complex of composite-fermion holes. We predict that these
bound states can be observed through a conductance resonance in experiments
involving a tunneling of an external electron into the fractional quantum Hall
liquid. A comment is made on the origin of the breakdown of the Fermi liquid
paradigm in the fractional hall liquid.Comment: 5 pages, 2 figure
Band Structure of the Fractional Quantum Hall Effect
The eigenstates of interacting electrons in the fractional quantum Hall phase
typically form fairly well defined bands in the energy space. We show that the
composite fermion theory gives insight into the origin of these bands and
provides an accurate and complete microscopic description of the strongly
correlated many-body states in the low-energy bands. Thus, somewhat like in
Landau's fermi liquid theory, there is a one-to-one correspondence between the
low energy Hilbert space of strongly interacting electrons in the fractinal
quantum Hall regime and that of weakly interacting electrons in the integer
quantum Hall regime.Comment: 10 page
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