4,787 research outputs found
Correlated metallic state in honeycomb lattice: Orthogonal Dirac semimetal
A novel gapped metallic state coined orthogonal Dirac semimetal is proposed
in the honeycomb lattice in terms of slave-spin representation of
Hubbard model. This state corresponds to the disordered phase of slave-spin and
has the same thermaldynamical and transport properties as usual Dirac semimetal
but its singe-particle excitation is gapped and has nontrivial topological
order due to the gauge structure. The quantum phase transition from
this orthogonal Dirac semimetal to usual Dirac semimetal is described by a
mean-field decoupling with complementary fluctuation analysis and its
criticality falls into the universality class of 2+1D Ising model while a large
anomalous dimension for the physical electron is found at quantum critical
point (QCP), which could be considered as a fingerprint of our fractionalized
theory when compared to other non-fractionalized approaches. As byproducts, a
path integral formalism for the slave-spin representation of Hubbard
model is constructed and possible relations to other approaches and the
sublattice pairing states, which has been argued to be a promising candidate
for gapped spin liquid state found in the numerical simulation, are briefly
discussed. Additionally, when spin-orbit coupling is considered, the
instability of orthogonal Dirac semimetal to the fractionalized quantum spin
Hall insulator (fractionalized topological insulator) is also expected. We hope
the present work may be helpful for future studies in slave-spin theory
and related non-Fermi liquid phases in honeycomb lattice.Comment: 12 pages,no figures, more discussions added. arXiv admin note: text
overlap with arXiv:1203.063
Analysis of the form-factors with light-cone QCD sum rules
In this article, we study the , ,
form-factors with the light-cone QCD sum rules, where the -meson light-cone
distribution amplitudes are used. In calculations, we observe that the
line-shapes of the -meson light-cone distribution amplitude
have significant impacts on the values of the form-factors, and expect to
obtain severe constraints on the parameters of the -meson light-cone
distribution amplitudes from the experimental data in the future.Comment: 19 pages, 6 figures, slight revisio
Analysis of the scalar doubly heavy tetraquark states with QCD sum rules
In this article, we perform a systematic study of the mass spectrum of the
scalar doubly charmed and doubly bottom tetraquark states using the QCD sum
rules.Comment: 17 pages, 24 figures, add more discussion
Analysis of the vertices , and with light-cone QCD sum rules
In this article, we calculate the strong coupling constants of the ,
and in the framework of the light-cone QCD sum
rules approach. The strong coupling constants of the meson-baryon-baryon are
the fundamental parameters in the one-boson exchange model which describes the
baryon-baryon interactions successfully. The numerical values are in agreement
with the existing calculations in part. The electric and magnetic
ratios deviate from the prediction of the vector meson dominance theory, the
SU(3) symmetry breaking effects are very large.Comment: 19 pages, 6 figures, revised version, add more discussions(Correct
writing errors
Thermodynamic Properties of Block Copolymer Electrolytes Containing Imidazolium and Lithium Salts
We report on the thermal properties, phase behavior, and thermodynamics of a series of polystyrene-block-poly(ethylene oxide) copolymers (SEO) mixed with the ionic species Li[N(SO_(2)CF_3)_2] (LiTFSI), imidazolium TFSI (ImTFSI), and an equimolar mixture of LiTFSI and ImTFSI (Mix). Differential scanning calorimetric scans reveal similar thermal behavior of SEO/LiTFSI and SEO/ImTFSI at the same salt concentrations. Phase behavior and thermodynamics were determined using a combination of small-angle X-ray scattering and birefringence. The thermodynamics of our mixtures can be mapped on to the theory of neat block copolymer phase behavior provided the Flory−Huggins interaction parameter, χ, between the blocks is replaced by an effective χ (χ_(eff)) that increases linearly with salt concentration. The phase behavior and the value of m, the slope of the χ_(eff) versus salt concentration data, were similar for SEO/LiTFSI, SEO/ImTFSI, and SEO/Mix blends. The theory developed by Wang [ J. Phys. Chem. B. 2008, 41, 16205] provides a basis for understanding the fundamental underpinnings of the measured value of m. We compare our experimental results with the predictions of this theory with no adjustable parameters
Effect of atmospheric turbulence on propagation properties of optical vortices formed by using coherent laser beam arrays
In this paper, we consider the effect of the atmospheric turbulence on the
propagation of optical vertex formed from the radial coherent laser beam array,
with the initially well-defined phase distribution. The propagation formula of
the radial coherent laser array passing through the turbulent atmosphere is
analytically derived by using the extended Huygens-Fresnel diffraction
integral. Based on the derived formula, the effect of the atmospheric
turbulence on the propagation properties of such laser arrays has been studied
in great detail. Our main results show that the atmospheric turbulence may
result in the prohibition of the formation of the optical vortex or the
disappearance of the formed optical vortex, which are very different from that
in the free space. The formed optical vortex with the higher topological charge
may propagate over a much longer distance in the moderate or weak turbulent
atmosphere. After the sufficient long-distance atmospheric propagation, all the
output beams (even with initially different phase distributions) finally lose
the vortex property and gradually become the Gaussian-shaped beams, and in this
case the output beams actually become incoherent light fields due to the
decoherence effect of the turbulent atmosphere.Comment: 10 pages, 5 figure
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