Phase structures of strong coupling lattice QCD with overlap fermions at finite temperature and chemical potential

We perform the first study of lattice QCD with overlap fermions at finite temperature $T$ and chemical potential $\mu$. We start from the Taylor expanded overlap fermion action, and derive in the strong coupling limit the effective free energy by mean field approximation. On the ($\mu,T$) plane and in the chiral limit, there is a tricritical point, separating the second order chiral phase transition line at small $\mu$ and large $T$, and first order chiral phase transition line at large $\mu$ and small $T$

Plasmon-exciton polaritons in 2D semiconductor/metal interfaces

The realization and control of polaritons is of paramount importance in the prospect of novel photonic devices. Here, we investigate the emergence of plasmon-exciton polaritons in hybrid structures consisting of a two-dimensional (2D) transition metal dichalcogenide (TMDC) deposited onto a metal substrate or coating a metallic thin-film. We determine the polaritonic spectrum and show that, in the former case, the addition of a top dielectric layer, and, in the latter, the thickness of the metal film,can be used to tune and promote plasmon-exciton interactions well within the strong coupling regime. Our results demonstrate that Rabi splittings exceeding 100 meV can be readily achieved in planar dielectric/TMDC/metal structures under ambient conditions. We thus believe that this work provides a simple and intuitive picture to tailor strong coupling in plexcitonics, with potential applications for engineering compact photonic devices with tunable optical properties.Comment: 6 pages, including 5 figures and reference

Berry phase effect in anomalous thermoelectric transport

We develop a theory of Berry phase effect in anomalous transport in ferromagnets driven by statistical forces such as the gradient of temperature or chemical potential. Here a charge Hall current arises from the Berry phase correction to the orbital magnetization rather than from the anomalous velocity which does not exist in the absence of a mechanical force. A finite-temperature formula for the orbital magnetization is derived, which enables us to provide an explicit expression for the off-diagonal thermoelectric conductivity, to establish the Mott relation between the anomalous Nernst and Hall effects, and to reaffirm the Onsager relations between reciprocal thermoelectric conductivities. A first-principles evaluation of our expression is carried out for the material CuCr$_2$Se$_{4-x}$Br$_x$, obtaining quantitative agreement with a recent experiment.Comment: Published version in PR

Mechanical Properties and Biological Responses of Bioactive Glass Ceramics Processed using Indirect SLS

This paper will report on research which aims to generate bone replacement components by processing bioactive glass-ceramic powders using indirect selective laser sintering. The indirect SLS route has been chosen as it offers the ability to tailor the shape of the implant to the implantation site, and two bioactive glass ceramic materials have been processed through this route: apatite-mullite and apatite-wollostanite. The results of bend tests, to investigate mechanical properties, and in vitro and in vivo experiments to investigate biological responses of the materials will be reported, and the suitability of completed components for implant will be assessed.Mechanical Engineerin

Effective Field Theory and Projective Construction for the Z_k Parafermion Fractional Quantum Hall States

The projective construction is a powerful approach to deriving the bulk and edge field theories of non-Abelian fractional quantum Hall (FQH) states and yields an understanding of non-Abelian FQH states in terms of the simpler integer quantum Hall states. Here we show how to apply the projective construction to the Z_k parafermion (Laughlin/Moore-Read/Read-Rezayi) FQH states, which occur at filling fraction \nu = k/(kM+2). This allows us to derive the bulk low energy effective field theory for these topological phases, which is found to be a Chern-Simons theory at level 1 with a U(M) \times Sp(2k) gauge field. This approach also helps us understand the non-Abelian quasiholes in terms of holes of the integer quantum Hall states.Comment: 7 page

Improved quantification of Chinese carbon fluxes using CO2/CO correlations in Asian outflow

[1] We use observed CO2:CO correlations in Asian outflow from the TRACE-P aircraft campaign (February–April 2001), together with a three-dimensional global chemical transport model (GEOS-CHEM), to constrain specific components of the east Asian CO2 budget including, in particular, Chinese emissions. The CO2/CO emission ratio varies with the source of CO2 (different combustion types versus the terrestrial biosphere) and provides a characteristic signature of source regions and source type. Observed CO2/CO correlation slopes in east Asian boundary layer outflow display distinct regional signatures ranging from 10–20 mol/mol (outflow from northeast China) to 80 mol/mol (over Japan). Model simulations using best a priori estimates of regional CO2 and CO sources from Streets et al. [2003] (anthropogenic), the CASA model (biospheric), and Duncan et al. [2003] (biomass burning) overestimate CO2 concentrations and CO2/CO slopes in the boundary layer outflow. Constraints from the CO2/CO slopes indicate that this must arise from an overestimate of the modeled regional net biospheric CO2 flux. Our corrected best estimate of the net biospheric source of CO2 from China for March–April 2001 is 3200 Gg C/d, which represents a 45 % reduction of the net flux from the CASA model. Previous analyses of the TRACE-P data had found that anthropogenic Chinese C

Thick branes with a nonminimally coupled bulk-scalar field

In this paper, we investigate thick branes with a nonminimally coupled background scalar field, whose solution is a single-kink or a double-kink. The effects of the nonminimal coupling constant $\xi$ on the structure of the thick branes and the localization of gravity, fermions, scalars and vectors are discussed. It is shown that each brane will split into two sub-branes as increasing the nonminimal coupling constant $\xi$. By investigating the tensor perturbation equations of gravity and the general covariant Dirac equation of fermions, we find that both the gravity zero mode and left-chiral fermion zero mode are localized at the center of the single-kink branes and localized between the two sub-branes generated by the double-kink, which indicates that the constant $\xi$ does not effect the localization of these zero modes. However, the zero mode of scalars is localized on each sub-brane (for both single-kink and double-kink branes) when $\xi$ is larger than its critical value $\xi_0$. The effects of the nonminimal coupling constant $\xi$ on the resonances of gravity and fermions with finite lifetime on the branes are also discussed.Comment: V2: 33 pages, 17 figures, 3 tables, published versio

Fermion Resonances on a Thick Brane with a Piecewise Warp Factor

In this paper, we mainly investigate the problems of resonances of massive KK fermions on a single scalar constructed thick brane with a piecewise warp factor matching smoothly. The distance between two boundaries and the other parameters are determined by one free parameter through three junction conditions. For the generalized Yukawa coupling $\eta\bar{\Psi}\phi^{k}\Psi$ with odd $k=1,3,5,...$, the mass eigenvalue $m$, width $\Gamma$, lifetime $\tau$, and maximal probability $P_{max}$ of fermion resonances are obtained. Our numerical calculations show that the brane without internal structure also favors the appearance of resonant states for both left- and right-handed fermions. The scalar-fermion coupling and the thickness of the brane influence the resonant behaviors of the massive KK fermions.Comment: V3: 15 pages, 7 figures, published versio