1,704 research outputs found

    Extended dual description of Mott transition beyond two-dimensional space

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    Motivated by recent work of Mross and Senthil [Phys. Rev. B \textbf{84}, 165126 (2011)] which provides a dual description for Mott transition from Fermi liquid to quantum spin liquid in two space dimensions, we extend their approach to higher dimensional cases, and we provide explicit formalism in three space dimensions. Instead of the vortices driving conventional Fermi liquid into quantum spin liquid states in 2D, it is the vortex lines to lead to the instability of Fermi liquid in 3D. The extended formalism can result in rich consequences when the vortex lines condense in different degrees of freedom. For example, when the vortex lines condense in charge phase degrees of freedom, the resulting effective fermionic action is found to be equivalent to that obtained by well-studied slave-particle approaches for Hubbard and/or Anderson lattice models, which confirm the validity of the extended dual formalism in 3D. When the vortex lines condense in spin phase degrees of freedom, a doublon metal with a spin gap and an instability to the unconventional superconducting pairing can be obtained. In addition, when the vortex lines condense in both phase degrees, an exotic doubled U(1) gauge theory occurs which describes a separation of spin-opposite fermionic excitations. It is noted that the first two features have been discussed in a similar way in 2D, the last one has not been reported in the previous works. The present work is expected to be useful in understanding the Mott transition happening beyond two space dimensions.Comment: 7 pages, no figure

    Effective-mass Klein-Gordon Equation for non-PT/non-Hermitian Generalized Morse Potential

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    The one-dimensional effective-mass Klein-Gordon equation for the real, and non-\textrm{PT}-symmetric/non-Hermitian generalized Morse potential is solved by taking a series expansion for the wave function. The energy eigenvalues, and the corresponding eigenfunctions are obtained. They are also calculated for the constant mass case.Comment: 14 page

    Magnetic Properties of J-J-J' Quantum Heisenberg Chains with Spin S=1/2, 1, 3/2 and 2 in a Magnetic Field

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    By means of the density matrix renormalization group (DMRG) method, the magnetic properties of the J-J-J^{\prime} quantum Heisenberg chains with spin S=1/2S=1/2, 1, 3/2 and 2 in the ground states are investigated in the presence of a magnetic field. Two different cases are considered: (a) when JJ is antiferromagnetic and JJ^{\prime} is ferromagnetic (i.e. the AF-AF-F chain), the system is a ferrimagnet. The plateaus of the magnetization are observed. It is found that the width of the plateaus decreases with increasing the ferromagnetic coupling, and disappears when % J^{\prime}/J passes over a critical value. The saturated field is observed to be independent of the ferromagnetic coupling; (b) when JJ is ferromagnetic and JJ^{\prime} is antiferromagnetic (i.e. the F-F-AF chain), the system becomes an antiferromagnet. The plateaus of the magnetization are also seen. The width of the plateaus decreases with decreasing the antiferromagnetic coupling, and disappears when J/JJ^{\prime}/J passes over a critical value. Though the ground state properties are quite different, the magnetization plateaus in both cases tend to disappear when the ferromagnetic coupling becomes more dominant. Besides, no fundamental difference between the systems with spin half-integer and integer has been found.Comment: 8 pages, 9 figures, to be published in J. Phys.: Condens. Matte

    Index for Three Dimensional Superconformal Field Theories and Its Applications

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    We review aspects of superconformal indices in three dimension. Three dimensional superconformal indices can be exactly computed by using localization method including monopole contribution, and can be applied to provide evidences for mirror duality, AdS_4/CFT_3 correspondence and global symmetry enhancement of strongly coupled gauge theories. After reviewing, we discuss the possibility of global symmetry enhancement in a finite rank of gauge group.Comment: 14 pages, Proceedings of the Seventh International Conference Quantum Theory and Symmetries (QTS-7) in Prague, Czech Republic, August, 2011; v2: minor modifications, discussion of supersymmetry enhancement of abelian ABJM theory by using an index were adde

    Duality between N=5 and N=6 Chern-Simons matter theory

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    We provide evidences for the duality between N=6{\cal N}=6 U(M)4×U(N)4U(M)_{4} \times U(N)_{-4} Chern-Simons matter theory and N=5{\cal N}=5 O(M^)2×USp(2N^)1O(\hat{M})_{2} \times USp(2\hat{N})_{-1} theory for a suitable M^,N^\hat{M},\hat{N} by working out the superconformal index, which shows perfect matching. For N=5{\cal N}=5 theories, we show that supersymmetry is enhanced to N=6{\cal N}=6 by explicitly constructing monopole operators filling in SO(6)RSO(6)_R RR-currents. Finally we work out the large NN index of O(2N)2k×USp(2N)kO(2N)_{2k} \times USp(2N)_{-k} and show that it exactly matches with the gravity index on AdS4×S7/DkAdS_4 \times S^7/D_k, which further provides additional evidence for the duality between the N=5{\cal N}=5 and N=6{\cal N}=6 theory for k=1k=1Comment: 15 pages; references adde

    First-order intertwining operators with position dependent mass and η\eta- weak-psuedo-Hermiticity generators

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    A Hermitian and an anti-Hermitian first-order intertwining operators are introduced and a class of η\eta-weak-pseudo-Hermitian position-dependent mass (PDM) Hamiltonians are constructed. A corresponding reference-target η\eta-weak-pseudo-Hermitian PDM -- Hamiltonians' map is suggested. Some η\eta-weak-pseudo-Hermitian PT -symmetric Scarf II and periodic-type models are used as illustrative examples. Energy-levels crossing and flown-away states phenomena are reported for the resulting Scarf II spectrum. Some of the corresponding η\eta-weak-pseudo-Hermitian Scarf II- and periodic-type-isospectral models (PT -symmetric and non-PT -symmetric) are given as products of the reference-target map.Comment: 11 pages, no figures, Revised/Expanded, more references added. To appear in the Int.J. Theor. Phy

    (1+1)-Dirac particle with position-dependent mass in complexified Lorentz scalar interactions: effectively PT-symmetric

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    The effect of the built-in supersymmetric quantum mechanical language on the spectrum of the (1+1)-Dirac equation, with position-dependent mass (PDM) and complexified Lorentz scalar interactions, is re-emphasized. The signature of the "quasi-parity" on the Dirac particles' spectra is also studied. A Dirac particle with PDM and complexified scalar interactions of the form S(z)=S(x-ib) (an inversely linear plus linear, leading to a PT-symmetric oscillator model), and S(x)=S_{r}(x)+iS_{i}(x) (a PT-symmetric Scarf II model) are considered. Moreover, a first-order intertwining differential operator and an η\eta-weak-pseudo-Hermiticity generator are presented and a complexified PT-symmetric periodic-type model is used as an illustrative example.Comment: 11 pages, no figures, revise

    Solvent Mediated Assembly of Nanoparticles Confined in Mesoporous Alumina

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    The controlled self-assembly of thiol stabilized gold nanocrystals in a mediating solvent and confined within mesoporous alumina was probed in situ with small angle x-ray scattering. The evolution of the self-assembly process was controlled reversibly via regulated changes in the amount of solvent condensed from an undersaturated vapor. Analysis indicated that the nanoparticles self-assembled into cylindrical monolayers within the porous template. Nanoparticle nearest-neighbor separation within the monolayer increased and the ordering decreased with the controlled addition of solvent. The process was reversible with the removal of solvent. Isotropic clusters of nanoparticles were also observed to form temporarily during desorption of the liquid solvent and disappeared upon complete removal of liquid. Measurements of the absorption and desorption of the solvent showed strong hysteresis upon thermal cycling. In addition, the capillary filling transition for the solvent in the nanoparticle-doped pores was shifted to larger chemical potential, relative to the liquid/vapor coexistence, by a factor of 4 as compared to the expected value for the same system without nanoparticles.Comment: 9 pages, 9 figures, appeared in Phys. Rev.

    Theory of Underdoped Cuprates

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    We develop a slave-boson theory for the t-J model at finite doping which respects an SU(2) symmetry -- a symmetry previously known to be important at half filling. The mean field phase diagram is found to be consistent with the phases observed in the cuprate superconductors, which contains d-wave superconductor, spin gap, strange metal, and Fermi liquid phases. The spin gap phase is best understood as the staggered flux phase, which is nevertheless translationally invariant for physical quantities. The electron spectral function shows small Fermi pockets at low doping which continuously evolve into the large Fermi surface at high doping concentrations.Comment: 4 pages, latex(revtex,epsf), 3 figure

    A protein kinase coordinates cycles of autophagy and glutaminolysis in invasive hyphae of the fungus \u3ci\u3eMagnaporthe oryzae\u3c/i\u3e within rice cells

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    The blast fungus Magnaporthe oryzae produces invasive hyphae in living rice cells during early infection, separated from the host cytoplasm by plantderived interfacial membranes. However, the mechanisms underpinning this intracellular biotrophic growth phase are poorly understood. Here, we show that the M. oryzae serine/threonine protein kinase Rim15 promotes biotrophic growth by coordinating cycles of autophagy and glutaminolysis in invasive hyphae. Alongside inducing autophagy, Rim15 phosphorylates NADdependent glutamate dehydrogenase, resulting in increased levels of α- ketoglutarate that reactivate target-of-rapamycin (TOR) kinase signaling, which inhibits autophagy. Deleting RIM15 attenuates invasive hyphal growth and triggers plant immunity; exogenous addition of α-ketoglutarate prevents these effects, while glucose addition only suppresses host defenses. Our results indicate that Rim15-dependent cycles of autophagic flux liberate α-ketoglutarate – via glutaminolysis – to reactivate TOR signaling and fuel biotrophic growth while conserving glucose for antioxidation-mediated host innate immunity suppression
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