103 research outputs found

    Sure success partial search

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    Partial search has been proposed recently for finding the target block containing a target element with fewer queries than the full Grover search algorithm which can locate the target precisely. Since such partial searches will likely be used as subroutines for larger algorithms their success rate is important. We propose a partial search algorithm which achieves success with unit probability

    Scalar products in generalized models with SU(3)-symmetry

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    We consider a generalized model with SU(3)-invariant R-matrix, and review the nested Bethe Ansatz for constructing eigenvectors of the transfer matrix. A sum formula for the scalar product between generic Bethe vectors, originally obtained by Reshetikhin [11], is discussed. This formula depends on a certain partition function Z(\{\lambda\},\{\mu\}|\{w\},\{v\}), which we evaluate explicitly. In the limit when the variables \{\mu\} or \{v\} approach infinity, this object reduces to the domain wall partition function of the six-vertex model Z(\{\lambda\}|\{w\}). Using this fact, we obtain a new expression for the off-shell scalar product (between a generic Bethe vector and a Bethe eigenvector), in the case when one set of Bethe variables tends to infinity. The expression obtained is a product of determinants, one of which is the Slavnov determinant from SU(2) theory. It extends a result of Caetano [13].Comment: 28 pages, 12 figures, greatly lengthened exposition in v3; 2 appendices and extra references adde

    Theory of spinor Fermi and Bose gases in tight atom waveguides

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    Divergence-free pseudopotentials for spatially even and odd-wave interactions in spinor Fermi gases in tight atom waveguides are derived. The Fermi-Bose mapping method is used to relate the effectively one-dimensional fermionic many-body problem to that of a spinor Bose gas. Depending on the relative magnitudes of the even and odd-wave interactions, the N-atom ground state may have total spin S=0, S=N/2, and possibly also intermediate values, the case S=N/2 applying near a p-wave Feshbach resonance, where the N-fermion ground state is space-antisymmetric and spin-symmetric. In this case the fermionic ground state maps to the spinless bosonic Lieb-Liniger gas. An external magnetic field with a longitudinal gradient causes a Stern-Gerlach spatial separation of the corresponding trapped Fermi gas with respect to various values of SzS_z.Comment: 4+ pages, 1 figure, revtex4. Submitted to PRA. Minor corrections of typos and notatio

    Universal correlations of one-dimensional interacting electrons in the gas phase

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    We consider dynamical correlation functions of short range interacting electrons in one dimension at finite temperature. Below a critical value of the chemical potential there is no Fermi surface anymore, and the system can no longer be described as a Luttinger liquid. Its low temperature thermodynamics is that of an ideal gas. We identify the impenetrable electron gas model as a universal model for the gas phase and present exact and explicit expressions for the asymptotics of correlation functions at small temperatures, in the presence of a magnetic field.Comment: 4 pages, Revte

    Higgs Structures of Dyonic Instantons

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    We study Higgs field configurations of dyonic instantons in spontaneously broken (4+1)-dimensional Yang-Mills theory. The adjoint scalar field solutions to the covariant Laplace equation in the ADHM instanton background are constructed in general noncanonical basis, and they are used to study explicitly the Higgs field configurations of dyonic instantons when the gauge fields are taken by Jackiw-Nohl-Rebbi instanton solutions. For these solutions corresponding to small instanton number we then consider in some detail the zero locus of the Higgs field, which describes the cross section of supertubes connecting parallel D4-branes in string theory. Also the information on the Higgs zeroes is used to discuss the residual gauge freedom concerning the Jackiw-Nohl-Rebbi solutions.Comment: 1+27 pages, 6 figure

    The Hubbard chain: Lieb-Wu equations and norm of the eigenfunctions

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    We argue that the square of the norm of the Hubbard wave function is proportional to the determinant of a matrix, which is obtained by linearization of the Lieb-Wu equations around a solution. This means that in the vicinity of a solution the Lieb-Wu equations are non-degenerate, if the corresponding wave function is non-zero. We further derive an action that generates the Lieb-Wu equations and express our determinant formula for the square of the norm in terms of the Hessian determinant of this action.Comment: 11 pages, Late

    Correlations in the impenetrable electron gas

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    We consider non-relativistic electrons in one dimension with infinitely strong repulsive delta function interaction. We calculate the long-time, large-distance asymptotics of field-field correlators in the gas phase. The gas phase at low temperatures is characterized by the ideal gas law. We calculate the exponential decay, the power law corrections and the constant factor of the asymptotics. Our results are valid at any temperature. They simplify at low temperatures, where they are easily recognized as products of free fermionic correlation functions with corrections arising due to the interaction.Comment: 17 pages, Late
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