Majorana fermions emerging from magnetic nanoparticles on a superconductor without spin-orbit coupling

There exists a variety of proposals to transform a conventional s-wave superconductor into a topological superconductor, supporting Majorana fermion mid-gap states. A necessary ingredient of these proposals is strong spin-orbit coupling. Here we propose an alternative system consisting of a one-dimensional chain of magnetic nanoparticles on a superconducting substrate. No spin-orbit coupling in the superconductor is needed. We calculate the topological quantum number of a chain of finite length, including the competing effects of disorder in the orientation of the magnetic moments and in the hopping energies, to identify the transition into the topologically nontrivial state (with Majorana fermions at the end points of the chain).Comment: 7 pages, 5 figure

Unsupervised Domain Adaptation for 3D Keypoint Estimation via View Consistency

In this paper, we introduce a novel unsupervised domain adaptation technique for the task of 3D keypoint prediction from a single depth scan or image. Our key idea is to utilize the fact that predictions from different views of the same or similar objects should be consistent with each other. Such view consistency can provide effective regularization for keypoint prediction on unlabeled instances. In addition, we introduce a geometric alignment term to regularize predictions in the target domain. The resulting loss function can be effectively optimized via alternating minimization. We demonstrate the effectiveness of our approach on real datasets and present experimental results showing that our approach is superior to state-of-the-art general-purpose domain adaptation techniques.Comment: ECCV 201

The Van der Waals interaction of the hydrogen molecule - an exact local energy density functional

We verify that the van der Waals interaction and hence all dispersion interactions for the hydrogen molecule given by: W"= -{A/R^6}-{B/R^8}-{C/R^10}- ..., in which R is the internuclear separation, are exactly soluble. The constants A=6.4990267..., B=124.3990835 ... and C=1135.2140398... (in Hartree units) first obtained approximately by Pauling and Beach (PB) [1] using a linear variational method, can be shown to be obtainable to any desired accuracy via our exact solution. In addition we shall show that a local energy density functional can be obtained, whose variational solution rederives the exact solution for this problem. This demonstrates explicitly that a static local density functional theory exists for this system. We conclude with remarks about generalising the method to other hydrogenic systems and also to helium.Comment: 11 pages, 13 figures and 28 reference

Critical exponents of the degenerate Hubbard model

We study the critical behaviour of the \SUN{} generalization of the one-dimensional Hubbard model with arbitrary degeneracy $N$. Using the integrability of this model by Bethe Ansatz we are able to compute the spectrum of the low-lying excitations in a large but finite box for arbitrary values of the electron density and of the Coulomb interaction. This information is used to determine the asymptotic behaviour of correlation functions at zero temperature in the presence of external fields lifting the degeneracy. The critical exponents depend on the system parameters through a $N\times N$ dressed charge matrix implying the relevance of the interaction of charge- and spin-density waves.Comment: 18 page

Single Color Centers Implanted in Diamond Nanostructures

The development of materials processing techniques for optical diamond nanostructures containing a single color center is an important problem in quantum science and technology. In this work, we present the combination of ion implantation and top-down diamond nanofabrication in two scenarios: diamond nanopillars and diamond nanowires. The first device consists of a 'shallow' implant (~20nm) to generate Nitrogen-vacancy (NV) color centers near the top surface of the diamond crystal. Individual NV centers are then isolated mechanically by dry etching a regular array of nanopillars in the diamond surface. Photon anti-bunching measurements indicate that a high yield (>10%) of the devices contain a single NV center. The second device demonstrates 'deep' (~1\mu m) implantation of individual NV centers into pre-fabricated diamond nanowire. The high single photon flux of the nanowire geometry, combined with the low background fluorescence of the ultrapure diamond, allows us to sustain strong photon anti-bunching even at high pump powers.Comment: 20 pages, 7 figure

Combination of Vorinostat with Whole-brain Radiotherapy in the Treatment of Brain Metastases

Background: A third of patients with solid malignancies develop brain metastases. Expected overall survival is 4-7 months depending on age, performance status, and extracranial disease. Standard treatment is controversial; however, the majority of patients receive wholebrain radiation therapy at some point. Vorinostat (suberoylanilide hydroxamic acid, SAHA), an FDA-approved HDAC inhibitor, has been demonstrated to radiosensitize tumor cells in vitro, as assessed by both radiation-induced DNA damage and clonogenic cell survival (Munshi et al. Molecular Cancer Therapeutics 5, 1967-1974, 2006). We have shown that vorinostat downregulates key genes involved in double-strand DNA repair (Rad50, Rad51, XRCC2, XRCC3, XRCC6), as assessed by quantitative PCR. This suggests that the drug’s mechanism of radiosensitization is epigenetic coordinated inhibition of the DNA repair process. We hypothesize that the combination of vorinostat with whole-brain radiation therapy will be both safe and efficacious. American Society of Clinical Oncology (ASCO) 46th Annual Meeting June 4-8, Chicago, IL

Controlling complex networks: How much energy is needed?

The outstanding problem of controlling complex networks is relevant to many areas of science and engineering, and has the potential to generate technological breakthroughs as well. We address the physically important issue of the energy required for achieving control by deriving and validating scaling laws for the lower and upper energy bounds. These bounds represent a reasonable estimate of the energy cost associated with control, and provide a step forward from the current research on controllability toward ultimate control of complex networked dynamical systems.Comment: 4 pages paper + 5 pages supplement. accepted for publication in Physical Review Letters; http://link.aps.org/doi/10.1103/PhysRevLett.108.21870

Discrimination between the superconducting gap and the pseudo-gap in Bi2212 from intrinsic tunneling spectroscopy in magnetic field

Intrinsic tunneling spectroscopy in high magnetic field ($H$) is used for a direct test of superconducting features in a quasiparticle density of states of high-$T_c$ superconductors. We were able to distinguish with a great clarity two co-existing gaps: (i) the superconducting gap, which closes as $H \to H_{c2}(T)$ and $T\to T_c(H)$, and (ii) the $c$-axis pseudo-gap, which does not change neither with $H$, nor $T$. Strikingly different magnetic field dependencies, together with previously observed different temperature dependencies of the two gaps ~\cite{Krasnov}, speak against the superconducting origin of the pseudo-gap.Comment: 4 pages, 4 eps figure

Granitoid rocks and associated coper skarn, Whycocomagh Mountain, Cape Breton Island, Nova Scotia

Mineralized (Fe-Cu-W-Mo) skarn in the Whycocomagh Mountain area is associated with a small pluton of Devonian (402±20 Ma) age, which intruded predominantly metasedimentary rocks of the Hadrynian George River Group. The pluton consists largely of granite porphyry with a marginal granodiorite to diorite zone, and minor porphyritlc granodiorite to monzodiorite dykes and pegmatite. The suite is calc-alkalic with I-type characteristics. Although weakly mineralized, the Whycocomagh Mountain pluton has features typical of plutons associated with porphyry-type Cu-Mo deposits. Calc-silicate rocks derived from marbles of the George River Group are the chief hosts for magnetlte ± chalcopyrlte ± scheelite ± molybdenite ± pyrite which occur in veinlets along fractures and as disseminated grains In adjacent alteration envelopes. Characteristics of the pluton and the skarn minerals suggest that the deposit is a copper skarn. RÉSUMÉ Un skarn minéralise (Fe-Cu-W-Mo), situe dans la région de la montagne Whycocomagh, est associé à une petite intrusion ignée d'âge Dévonien (402±20 m.a.) qui pénétre des roches, principalement des métasédiments, du groupe George River (Hadrynien). Le pluton consiste surtout en un granite porphyrique accompagne d'une zone marginale (granodiorite à diorite), de dykes mineurs (granodiorite à monzodiorite porphyrique) et de pegmatite. L'ensemble est calco-alcalln et de "type 1". Blen que faiblement minéralise, le pluton Whycocomagh Mountain possède lea caractérlstiques typiques des plutons associés aux dépôts porphyrlques de type Cu-Mo. Les calco-sflicates dérives des marbres du groupe George River sont les notes principaux du cortege for magnétite ± chalcopyrlte ± scheelite ± molybdenite ± pyrite que L’on retrouve dans des veinules le long des fractures et disséminés dans les enveloppes d'alteratlon volsines. Les caractérlstiques du pluton ainsi que la minéralogle du skarn font croire qu'il s'agit d'un dépôt de skarn cuprifère. (Tradult par le Journal

Strange nonchaotic attractors in noise driven systems

Strange nonchaotic attractors (SNAs) in noise driven systems are investigated. Before the transition to chaos, due to the effect of noise, a typical trajectory will wander between the periodic attractor and its nearby chaotic saddle in an intermittent way, forms a strange attractor gradually. The existence of SNAs is confirmed by simulation results of various critera both in map and continuous systems. Dimension transition is found and intermittent behavior is studied by peoperties of local Lyapunov exponent. The universality and generalization of this kind of SNAs are discussed and common features are concluded