21,928 research outputs found
Spin-Charge Decoupling and Orthofermi Quantum Statistics
Currently Gutzwiller projection technique and nested Bethe ansatz are two
main methods used to handle electronic systems in the infinity limit. We
demonstrate that these two approaches describe two distinct physical systems.
In the nested Bethe ansatz solutions, there is a decoupling between the spin
and charge degrees of freedom. Such a decoupling is absent in the Gutzwiller
projection technique. Whereas in the Gutzwiller approach, the usual
antisymmetry of space and spin coordinates is maintained, we show that the
Bethe ansatz wave function is compatible with a new form of quantum statistics,
viz., orthofermi statistics. In this statistics, the wave function is
antisymmetric in spatial coordinates alone. This feature ultimately leads to
spin-charge decoupling.Comment: 12 pages, LaTex Journal_ref: A slightly abridged version of this
paper has appeared as a brief report in Phys. Rev. B, Vol. 63, 132405 (2001
AN ANALYSIS OF TAX-DEFERRED RETIREMENT SAVINGS OF FARM HOUSEHOLDS
The retiring farmer generally tries to balance the desire to keep the farm intact as a going concern with the need for a secure assets portfolio to finance retirement. This problem becomes more complex in situations where younger family members choose not to be active in the farm business. Tax-deferred savings are potentially an important component of a retirement plan and could represent a very substantial increase in tax-free assets for many individuals. This study examines the tax deferred retirement savings of farm households. The model is estimated using Agricultural Resource Management Survey (ARMS) 1999 farm-level national data and the Double-Hurdle estimation method. Results indicate that farm household's source of income, age of the farm operator, marginal tax rate, regional location, and participation in government programs are factors that significantly affect investment in tax-deferred savings.Farm Management,
Construction of Pena’s DP2-Based Ordinal Synthetic Indicator When Partial Indicators are Rank Scores
Anisotropic cosmological models with two fluids
In this paper, aniostropic dark energy cosmological models have been
constructed in a Bianchi-V space-time with the energy momentum tensor
consisting of two non-interacting fluids namely bulk viscous fluid and dark
energy fluid. Two different models are constructed based on the power law
cosmology and de Sitter universe. The constructed model also embedded with
different pressure gradients along different spatial directions. The variable
equation of state (EoS) parameter, skewness parameters for both the models are
obtained and analyzed. The physical properties of the models obtained with the
use of scale factors of power law and de Sitter law are also presented.Comment: 10 pages, 12 figure
Qubit(s) transfer in helical spin chains
Qubit(s) transfer through a helical chain is studied. We consider the
transfer of a single state and Bell states across a multiferroic spin chain and
the possibility of an electric field control of the fidelity of the single
state and the Bell pairs. We analyze pure and imperfect multiferroic spin
chains. A scheme for an efficient transfer of spin states through a
multiferroic channel relies on kicking by appropriate electric field pulses at
regular interval. This electric field pulse sequence undermines the effect of
impurity on the fidelity and improves the state transfer through the helical
chain.Comment: 7 pages, 10 figure
Interior gap superfluidity in a two-component Fermi gas of atoms
A new superfluid phase in Fermi matter, termed as "interior gap" (IG) or
"breached pair", has been recently predicted by Liu and Wilczek [Phys.Rev.Lett.
{\bf 90}, 047002 (2003)]. This results from pairing between fermions of two
species having essentially different Fermi surfaces. Using a nonperturbative
variational approach, we analyze the features, such as energy gap, momentum
distributions, and elementary excitations associated with the predicted phase.
We discuss possible realization of this phase in two-component Fermi gases in
an optical trap.Comment: 5 page
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