Topological magnetoplasmon

Classical wave fields are real-valued, ensuring the wave states at opposite frequencies and momenta to be inherently identical. Such a particle-hole symmetry can open up new possibilities for topological phenomena in classical systems. Here we show that the historically studied two-dimensional (2D) magnetoplasmon, which bears gapped bulk states and gapless one-way edge states near zero frequency, is topologically analogous to the 2D topological p+\Ii p superconductor with chiral Majorana edge states and zero modes. We further predict a new type of one-way edge magnetoplasmon at the interface of opposite magnetic domains, and demonstrate the existence of zero-frequency modes bounded at the peripheries of a hollow disk. These findings can be readily verified in experiment, and can greatly enrich the topological phases in bosonic and classical systems.Comment: 12 pages, 6 figures, 1 supporting materia

Stability of multi-electron bubbles in liquid helium

The stability of multi-electron bubbles in liquid helium is investigated theoretically. We find that multi-electron bubbles are unstable against fission whenever the pressure is positive. It is shown that for moving bubbles the Bernoulli effect can result in a range of pressures over which the bubbles are stable.Comment: 7 pages, 5 figure

Terahertz plasmonics in ferroelectric-gated graphene

Inspired by recent advancement of ferroelectric-gated memories and transistors, we propose a design of ferroelectric-gated nanoplasmonic devices based on graphene sheets clamped in ferroelectric crystals. We show that the two-dimensional plasmons in graphene can strongly couple with the phonon-polaritons in ferroelectrics, leading to characteristic modal wavelength of the order of 100–200 nm at low temperature and low-THz frequencies albeit with an appreciable dissipation. By patterning the ferroelectrics into different domains, one can produce compact on-chip plasmonic waveguides, which exhibit negligible crosstalk even at 20 nm separation distance. Harnessing the memory effect of ferroelectrics, low-power operation can be achieved on these plasmonic waveguides.National Science Foundation (U.S.) (ECCS Award 1028568)United States. Air Force Office of Scientific Research. Multidisciplinary University Research Initiative (Award FA9550-12-1-0488

Glycine equivalent and threonine inclusions in reduced-crude protein, maize-based diets impact on growth performance, fat deposition, starch-protein digestive dynamics and amino acid metabolism in broiler chickens

Maize-based diets were formulated to contain 208, 193, 179 and 165 g/kg crude protein (CP) were prepared and the last diet was supplemented with 4.33 g/kg glycine equivalents and 1.10 g/ kg threonine, individually and in combination, to provide seven dietary treatments. Each dietary treatment was offered to eight replicate cages (6 birds per cage) of off-sex, male Ross 308 chickens from 7 to 35 days post-hatch. The transition from 208 to 165 g/kg CP diets numerically compromised weight gain and feed conversion ratios (FCR) by 5.41% and 3.44%, respectively, and linearly increased relative fat-pad weights from 7.62 to 13.31 g/kg. The same transition linearly increased ileal starch:protein disappearance rate ratios from 2.01 to 3.23 (r=-0.823;

Two-dimensional superconductivity and anisotropic transport at KTaO ₃ (111) interfaces

A superconducting interface Interfaces between materials can harbor quantum states that belong to neither of the materials. A classic example is the superconducting interface between two insulating oxides, LaAlO 3 and SrTiO 3 , with a critical temperature of around 200 millikelvin. Liu et al. observed superconductivity at a different interface—formed between KTaO 3 as a substrate and an overlayer of either EuO or LaAlO 3 —at a considerably higher temperature of about 2 kelvin. Transport measurements displayed anisotropy, which may indicate an unusual superconducting state. Science , this issue p. 716 </jats:p