5,020 research outputs found
Persistent spin current and entanglement in the anisotropic spin ring i
We investigate the ground state persistent spin current and the pair
entanglement in one-dimensional antiferromagnetic anisotropic Heisenberg ring
with twisted boundary conditions. Solving Bethe ansatz equations numerically,
we calculate the dependence of the ground state energy on the total magnetic
flux through the ring, and the resulting persistent current. Motivated by
recent development of quantum entanglement theory, we study the properties of
the ground state concurrence under the influence of the flux through the
anisotropic Heisenberg ring. We also include an external magnetic field and
discuss the properties of the persistent current and the concurrence in the
presence of the magnetic field.Comment: 5 pages, 8 figure
Large-N scaling behavior of the quantum fisher information in the Dicke model
Quantum Fisher information (QFI) of the reduced two-atom state is employed to
capture the quantum criticality of the superradiant phase transition in the
Dicke model in the infinite size and finite- systems respectively. The
analytical expression of the QFI of its ground state is evaluated explicitly.
And finite-size scaling analysis is performed with the large accessible system
size due to the effective bosonic coherent-state technique. We also investigate
the large-size scaling behavior of the scaled QFI of the reduced -atom state
and show the accurate exponent.Comment: 6pages,2figure
Representations of Hopf Ore extensions of group algebras and pointed Hopf algebras of rank one
In this paper, we study the representation theory of Hopf-Ore extensions of
group algebras and pointed Hopf algebras of rank one over an arbitrary field
. Let H=kG(\chi, a,\d) be a Hopf-Ore extension of and a rank one
quotient Hopf algebra of , where is a field, is a group, is a
central element of and is a -valued character for with
. We first show that the simple weight modules over and
are finite dimensional. Then we describe the structures of all simple weight
modules over and , and classify them. We also consider the
decomposition of the tensor product of two simple weight modules over into
the direct sum of indecomposable modules. Furthermore, we describe the
structures of finite dimensional indecomposable weight modules over and
, and classify them. Finally, when is a primitive -th root of
unity for some , we determine all finite dimensional indecomposable
projective objects in the category of weight modules over .Comment: arXiv admin note: substantial text overlap with arXiv:1206.394
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