Electron teleportation with quantum dot arrays

An electron teleportation protocol, inspired by the scenario by Bennett et al., is proposed in a mesoscopic set-up. A superconducting circuit allows to both inject and measure entangled singlet electron pairs in an array of three normal quantum dots. The selection of the teleportation process is achieved in the steady state with the help of two superconducting dots and appropriate gating. Teleportation of the electron spin is detected by measuring the spin-polarized current through the normal dot array. This current is perfectly correlated to the pair current flowing inside the superconducting circuit. The classical channel required by Bennett's protocol, which signals the completion of a teleportation cycle, is identified with the detection of an electron charge in the superconducting circuit.Comment: revised version, 4 pages, 2 figure

Operators on superspaces and generalizations of the Gelfand-Kolmogorov theorem

(Write-up of a talk at the Bialowieza meeting, July 2007.) Gelfand and Kolmogorov in 1939 proved that a compact Hausdorff topological space $X$ can be canonically embedded into the infinite-dimensional vector space $C(X)^*$, the dual space of the algebra of continuous functions $C(X)$ as an "algebraic variety" specified by an infinite system of quadratic equations. Buchstaber and Rees have recently extended this to all symmetric powers \Sym^n(X) using their notion of the Frobenius $n$-homomorphisms. We give a simplification and a further extension of this theory, which is based, rather unexpectedly, on results from super linear lgebra.Comment: LaTeX, 7 pages. Based on a talk at the Bialowieza meeting, July 200

Parameterized Uniform Complexity in Numerics: from Smooth to Analytic, from NP-hard to Polytime

The synthesis of classical Computational Complexity Theory with Recursive Analysis provides a quantitative foundation to reliable numerics. Here the operators of maximization, integration, and solving ordinary differential equations are known to map (even high-order differentiable) polynomial-time computable functions to instances which are `hard' for classical complexity classes NP, #P, and CH; but, restricted to analytic functions, map polynomial-time computable ones to polynomial-time computable ones -- non-uniformly! We investigate the uniform parameterized complexity of the above operators in the setting of Weihrauch's TTE and its second-order extension due to Kawamura&Cook (2010). That is, we explore which (both continuous and discrete, first and second order) information and parameters on some given f is sufficient to obtain similar data on Max(f) and int(f); and within what running time, in terms of these parameters and the guaranteed output precision 2^(-n). It turns out that Gevrey's hierarchy of functions climbing from analytic to smooth corresponds to the computational complexity of maximization growing from polytime to NP-hard. Proof techniques involve mainly the Theory of (discrete) Computation, Hard Analysis, and Information-Based Complexity

Comment on: "Estimating the Hartree-Fock limit from finite basis set calculations" [Jensen F (2005) Theor Chem Acc 113:267]

We demonstrate that a minor modification of the extrapolation proposed by Jensen [(2005): Theor Chem Acc 113:267] yields very reliable estimates of the Hartree-Fock limit in conjunction with correlation consistent basis sets. Specifically, a two-point extrapolation of the form $E_{HF,L}=E_{HF,\infty}+A(L+1)\exp(-9\sqrt{L})$ yields HF limits $E_{HF,\infty}$ with an RMS error of 0.1 millihartree using aug-cc-pVQZ and aug-cc-pV5Z basis sets, and of 0.01 millihartree using aug-cc-pV5Z and aug-cc-pV6Z basis sets.Comment: Theoretical Chemistry Accounts, in pres

Ejaculate allocation by male sand martins, Riparia riparia

Males of many species allocate sperm to ejaculates strategically in response to variation in the risk and intensity of sperm competition. The notable exception is passerine birds, in which evidence for strategic allocation is absent. Here we report the results of a study testing for strategic ejaculate allocation in a passerine bird, the sand martin (Riparia riparia). Natural ejaculates were collected from males copulating with a model female. Ejaculates transferred in the presence of a rival male contained significantly more sperm than ejaculates transferred in the absence of a rival male. There was no evidence that this difference was due to the confounding effects of the year of ejaculate collection, the identity of the model female, the colony, the stage of season or the period of the day in which ejaculates were collected. A more detailed examination of the ejaculate patterns of individual males, achieved by the DNA profiling of ejaculates, provided additional evidence for strategic allocation of sperm

Interference of an array of atom lasers

We report on the observation of interference of a series of atom lasers. A comb-like array of coherent atomic beams is generated by outcoupling atoms from distinct Bose-Einstein condensates confined in the independent sites of a mesoscopic optical lattice. The observed interference signal arises from the spatial beating of the overlapped atom laser beams, which is sampled over a vertical region corresponding to 2 ms of free fall time. The average relative de Broglie frequency of the atom lasers was measured.Comment: 3 figure

Broadband enhancement of the magneto-optical activity of hybrid Au loaded Bi:YIG

We unravel the underlying near-field mechanism of the enhancement of the magneto-optical activity of bismuth-substituted yttrium iron garnet films (Bi:YIG) loaded with gold nanoparticles. The experimental results show that the embedded gold nanoparticles lead to a broadband enhancement of the magneto-optical activity with respect to the activity of the bare Bi:YIG films. Full vectorial near- and far-field simulations demonstrate that this broadband enhancement is the result of a magneto-optically enabled cross-talking of orthogonal localized plasmon resonances. Our results pave the way to the on-demand design of the magneto-optical properties of hybrid magneto-plasmonic circuitry.Comment: 6 Pages, 3 Figure

ANALISIS USAHA PENANGKAPAN IKAN DENGAN ALAT TANGKAP RAMBAT DI KELURAHAN KERENG BANGKIRAI

Penelitian ini bertujuan untuk menganalisis besarnya biaya, keuntungan dan tingkat kelayakan dari usaha penangkapan ikan dengan alat tangkap ikan rambat yang dioperasikan di Sungai Sabangau, Kelurahan Kereng Bangkirai, Kota Palangka Raya.  Penelitian ini menggunakan metode deskriptif yang bersifat survei dengan cara melakukan wawancara terstruktur secara langsung dengan responden.  Wawancara menggunakan daftar pertanyaan (quisioner) kepada nelayan pengguna alat tangkap rambat.  Hasil analisis finansial diperoleh bahwa modal usaha yang dikeluarkan dalam kegiatan usaha perikanan rambat di Kelurahan Kereng Bangkirai berkisar Rp.8.741.000,- – Rp.12.688.857,- per tahun dengan keuntungan rata-rata Rp.42.552.512,- per tahun atau Rp. 3.546.043,- per bulan dengan menjual hasil tangkapan ke pengepul ikan. Analisis kelayakan usaha diketahui dengan nilai rasio R/C  sebesar 4,30 dan nilai PP (payback period) sebesar 0,31 tahun.  Selanjutnya, nilai rata-rata BEP produksi perikanan dan BEP harga masing-masing sebesar 332 kg dan Rp. 9.185 lebih kecil dibandingkan dengan nilai rata-rata BEP produksi dan BEP harga dari hasil alat tangkap rambat masing-masing sebesar 1.402,29 kg dan Rp. 39.286.  Hal ini menunjukkan bahwa kegiatan perikanan rambat di Kelurahan Kereng Bangkirai, Kota Palangka Raya layak untuk diteruskan dan dikembangkan

Higher Poisson Brackets and Differential Forms

We show how the relation between Poisson brackets and symplectic forms can be extended to the case of inhomogeneous multivector fields and inhomogeneous differential forms (or pseudodifferential forms). In particular we arrive at a notion which is a generalization of a symplectic structure and gives rise to higher Poisson brackets. We also obtain a construction of Koszul type brackets in this setting.Comment: LaTeX, 13 pages. Based on report at the XXVII Workshop on Geometric Methods in Physics (Bialowieza, Poland, 29 June to 5 July 2008