Skip to content

January 2007 arXiv papers — page 6

Showing 501–600 of 4,539 papers

  1. G Aragon-Gonzalez, A. Canales-Palma, A. Leon-Galicia, J. R. Morales-Gomez

    In this work we include, for the Carnot cycle, irreversibilities of linear finite rate of heat transferences between the heat engine and its reservoirs, heat leak between the reservoirs and internal dissipations of the working fluid. A first optimization of the power output, the efficiency and ecological function of an irreversible Carnot cycle, with respect

  2. Feng Fu, Xiaojie Chen, Lianghuan Liu, Long Wang

    We investigate two paradigms for studying the evolution of cooperation--Prisoner's Dilemma and Snowdrift game in an online friendship network obtained from a social networking site. We demonstrate that such social network has small-world property and degree distribution has a power-law tail. Besides, it has hierarchical organizations and exhibits disasso

  3. Feng Fu, Xiaojie Chen, Lianghuan Liu, Long Wang

    We consider the coupled dynamics of the adaption of network structure and the evolution of strategies played by individuals occupying the network vertices. We propose a computational model in which each agent plays a $n$-round Prisoner's Dilemma game with its immediate neighbors, after that, based upon self-interest, partial individuals may punish their

  4. I. Gerhardt, G. Wrigge, M. Agio, P. Bushev

    We present scanning near-field extinction spectra of single molecules embedded in a solid matrix. By varying the molecule-tip separation, we modify the line shape of the spectra, demonstrating the coherent nature of the interaction between the incident laser light and the excited state of the molecule. We compare the measured data with the outcome of numeric

  5. V. A. Yerokhin, A. N. Artemyev, V. M. Shabaev

    A systematic QED treatment of electron correlation is presented for ions along the lithium isoelectronic sequence. We start with the zeroth-order approximation that accounts for a part of the electron-electron interaction by a local model potential introduced into the Dirac equation. The residual electron correlation is treated by perturbation theory. Rigoro

  6. Stephan Fauve, Francois Petrelis

    We consider magnetic fields generated by homogeneous isotropic and parity invariant turbulent flows. We show that simple scaling laws for dynamo threshold, magnetic energy and Ohmic dissipation can be obtained depending on the value of the magnetic Prandtl number.

  7. Xiaojie Chen, Feng Fu, Long Wang

    We study the evolutionary Prisoner's Dilemma game on scale-free networks for different initial distributions. We consider three types of initial distributions for cooperators and defectors: initially random distribution with different frequencies of defectors; intentional organization with defectors initially occupying the most connected nodes with diffe

  8. Xiaojie Chen, Feng Fu, Long Wang, Tianguang Chu

    To our knowledge, the populations are generally assumed to be homogeneous in the traditional approach to evolutionary game dynamics. Here, we focus on the inhomogeneous populations. A simple model which can describe the inhomogeneity of the populations and a microscopic process which is similar to Moran Process are presented. By studying the replicator dynam

  9. Lianghuan Liu, Feng Fu, Long Wang

    In this paper, we study the information propagation in an empirical blogging network by game-theoretical approach. The blogging network has small-world property and is scale-free. Individuals in the blogosphere coordinate their decisions according to their idiosyncratic preferences and the choices of their neighbors. We find that corresponding to different i

  10. Jing Wang, Feng Fu, Long Wang, Guangming Xie

    We propose a model for evolutionary game dynamics with three strategies $A$, $B$ and $C$ in the framework of Moran process in finite populations. The model can be described as a stochastic process which can be numerically computed from a system of linear equations. Furthermore, to capture the feature of the evolutionary process, we define two essential varia

  11. Agapi Emmanouilidou

    In a quasiclassical framework, we formulate the double energy differential cross sections for the Coulomb four-body problem. We present results for the triple photoionization from the Li ground state at 220.5, 115, 50 and 3.8 eV excess energies. With the energy of one of the electrons kept fixed, the double energy differential cross sections at 220.5 and 115

  12. J. P. Hilbert, N. Black, T. Barnes, E. S. Swanson

    Charmonium dissociation cross sections due to flavor-exchange charmonium-baryon scattering are computed in the constituent quark model. We present results for inelastic $J/ψN$ and $η_c N$ scattering amplitudes and cross sections into 46 final channels, including final states composed of various combinations of $D$, $D^*$, $Σ_c$, and $Λ_c$. These results are

  13. N. Pillet, N. Sandulescu, P. Schuck

    With realistic HFB calculations, using the D1S Gogny force, we reveal a generic behavior of concentration of small sized Cooper pairs (2-3 fm) in the surface of superfluid nuclei. This study confirms and extends previous results given in the literature that use more schematic approaches.

  14. C. Beck

    This submission has been withdrawn by arXiv administrators because it is a duplicate of nucl-th/0610004.

  15. T. Mersmann, A. Khoukaz, M. Büscher, D. Chiladze

    The differential and total cross sections for the d+p->3He+eta reaction have been measured in a high precision high statistics COSY-ANKE experiment near threshold using a continuous beam energy ramp up to an excess energy Q of 11.3 MeV with essentially 100% acceptance. The kinematics allowed the mean value of Q to be determined to about 9 keV. Evidence is fo

  16. Lijuan Ruan

    New physics results with identified particles at STAR are presented. Measurements at low $p_T$ address bulk properties of the collision, while those at high $p_T$ address jet energy loss in the bulk matter produced. Between these extremes, measurements at intermediate $p_T$ address the interplay between jets and the bulk. We highlight: measurements of $v_2$

  17. M. J. Horner

    We present a study of low- and intermediate-p$_T$ correlated azimuthal angular distributions in Au+Au collisions at $\sqrt{s_{NN}}=200 \rm{GeV}$ from STAR. The near-side associated yields in Au+Au collisions are found to be strongly enhanced, due to contributions from large $Δη$. The enhancement is reduced for high \pTtrig. We show a strong broadening and en

  18. Maria Przybylska

    n this paper we formulate necessary conditions for the integrability in the Jacobi sense of Newton equations $\ddot \vq=-\vF(\vq)$, where $\vq\in\C^n$ and all components of $\vF$ are polynomial and homogeneous of the same degree $l$. These conditions are derived from an analysis of the differential Galois group of the variational equations along special part

  19. Andrzej J. Maciejewski, Maria Przybylska, Haruo Yoshida

    We consider a natural Hamiltonian system of $n$ degrees of freedom with a homogeneous potential. Such system is called partially integrable if it admits $1<l<n$ independent and commuting first integrals, and it is called super-integrable if it admits $n+l$, $0<l<n$ independent first integrals such that $n$ of them commute. We formulate two theorems which giv

  20. Toshiya Takami, Hiroshi Fujisaki

    We examine random matrix systems driven by an external field in view of optimal control theory (OCT). By numerically solving OCT equations, we can show that there exists a smooth transition between two states called &#34;moving bases&#34; which are dynamically related to initial and final states. In our previous work [J. Phys. Soc. Jpn. 73 (2004) 3215-3216;

  21. Yohei Tutiya, Masahiro Kanai

    In this paper, we present exact shock solutions of a coupled system of delay differential equations, which was introduced as a traffic-flow model called {\it the car-following model}. We use the Hirota method, originally developed in order to solve soliton equations. %While, with a periodic boundary condition, this system has % a traveling-wave solution give

  22. Walid K. Abou Salem

    The fluctuations of macroscopic observables in quantum systems which are in a nonequilibrium steady state are studied rigorously in the thermodynamic limit. In particular, the nonequilibrium steady state (NESS) of a quantum spin system that is composed of two infinite reservoirs at different temperatures coupled in a bounded region is considered. Under suita

  23. Catherine Greenhill, Fred B. Holt, Nicholas Wormald

    We investigate the following vertex percolation process. Starting with a random regular graph of constant degree, delete each vertex independently with probability p, where p=n^{-alpha} and alpha=alpha(n) is bounded away from 0. We show that a.a.s. the resulting graph has a connected component of size n-o(n) which is an expander, and all other components are

  24. S. Favorov, A. Rashkovskii, L. Ronkin

    A notion of almost periodic current is introduced, as well as a notion of almost periodic holomorphic chain proceeded from that definition. Such a chain can be defined either as a special case of almost periodic currents or as a holomorphic chain whose trace measure is an almost periodic distribution. It is shown that in general situation almost periodicity

  25. Cristian D. Gonzalez-Aviles

    Let $k$ be a perfect field and let $p$ be a prime number different from the characteristic of $k$. Let $C$ be a smooth, projective and geometrically integral $k$-curve and let $X$ be a Severi-Brauer $C$-scheme of relative dimension $p-1$ . In this paper we show that $CH^{d}(X)_{\rm{tors}}$ contains a subgroup isomorphic to $CH_{0}(X/C)$ for every $d$ in the

  26. S. Favorov, N. Parfyonova

    H.Bohr in 1930 proved that if a holomorphic bounded function on a strip is almost periodic on a straight line in the strip, then it is almost periodic on the whole strip. We find some conditions when the result is valid for holomorphic mappings of tube domains to various complex manifolds.

  27. Rémi Carles

    We study the flow map associated to the cubic Schrodinger equation in space dimension at least three. We consider initial data of arbitrary size in $H^s$, where $0<s<s_c$, $s_c$ the critical index, and perturbations in $H^\si$, where $\si<s_c$ is independent of $s$. We show an instability mechanism in some Sobolev spaces of order smaller than $s$. The analys

  28. Atanas Stefanov

    In this work, we develop $L^p$ boundedness theory for pseudodifferential operators with rough (not even continuous in general) symbols in the $x$ variable. Moreover, the $B(L^p)$ operator norms are estimated explicitly in terms of scale invariant quantities involving the symbols. All the estimates are shown to be sharp with respect to the required smoothness

  29. Peng Gao

    We study certain sequences involving sums of powers of positive integers and in connection with this, we give examples to show that power majorization does not imply majorization.

  30. Temitope Gbolahan Jaiyeola

    If two loops are isomorphic, then it is shown that their holomorphs are also isomorphic. Conversely, it is shown that if their holomorphs are isomorphic, then the loops are isotopic. It is shown that a loop is a Smarandache loop if and only if its holomorph is a Smarandache loop. This statement is also shown to be true for some weak Smarandache loops(inverse

  31. Stefanie Petermichl, Brett D. Wick

    We show that the Lusin area integral or the square function on the unit ball of $\C^n$, regarded as an operator in weighted space $L^2(w)$ has a linear bound in terms of the invariant $A_2$ characteristic of the weight. We show a dimension-free estimate for the ``area-integral&#39;&#39; associated to the weighted $L^2(w)$ norm of the square function. We prov

  32. Stefanie Petermichl, Sergei Treil, Brett D. Wick

    In this note we present a new proof of the Carleson Embedding Theorem on the unit disc and unit ball. The only technical tool used in the proof of this fact is Green&#39;s formula. The starting point is that every Carleson measure gives rise to a bounded subharmonic function. Using this function we construct a new related Carleson measure that allows for a s

  33. Hendrik Hubrechts

    We present a deterministic algorithm that computes the zeta function of a nonsupersingular elliptic curve E over a finite field with p^n elements in time quasi-quadratic in n. An older algorithm having the same time complexity uses the canonical lift of E, whereas our algorithm uses rigid cohomology combined with a deformation approach. An implementation in

  34. Philippe Briand, Fulvia Confortola

    This paper is devoted to the study of the differentiability of solutions to real-valued backward stochastic differential equations (BSDEs for short) with quadratic generators driven by a cylindrical Wiener process. The main novelty of this problem consists in the fact that the gradient equation of a quadratic BSDE has generators which satisfy stochastic Lips

  35. Daguang Chen

    For a compact spin manifold $M$ isometrically embedded into Euclidean space, we derive the extrinsic estimates from above and below for eigenvalues of the Dirac operators, which depend on the second fundamental form of the embedding. We also show the bounds of the ratio of the eigenvalues.

  36. François Ollivier, Saïd Moutaouakil, Brahim Sadik

    We provide a class of methods for the identification of a linear system with delay of the shape $x^{(n)}(t) = \sum_{i=0}^{n-1}a_{i}x^{(i)}(t) + bu(t-h)$. They allow the simultaneous identification of the parameters and delay, the observation of $x$ and its derivatives, knowing only generic input $u$ and output $x$. They are robust to the noise. Used in conti

  37. Marc Reversat

    We give a description of the rational representations of the differential Galois group of a Picard-Vessiot extension.

  38. Daguang Chen

    Under two boundary conditions, the generalized Atiyah-Patodi-Singer boundary condition and the modified generalized -Atiyah-Patodi-Singer boundary condition, we get the lower bounds for the eigenvalues of the fundamental Dirac operator on compact spin manifolds with nonempty boundary.

  39. François Ollivier, Brahim Sadik

    We show that Jacobi&#39;s bound for the order of a system of ordinary differential equations stands in the case of a diffiety defined by a quasi-regular system. We extend the result when there are less equations than variables and characterize the case when the bound is reached.

  40. Ricard Martí, Enric Nart

    For a fixed dimension $N$ we compute the generating function of the numbers $t_N(n)$ (respectively $\bar{t}_N(n)$) of $PGL_{N+1}(k)$-orbits of rational $n$-sets (respectively rational $n$-multisets) of the projective space $\mathb{P}^N$ over a finite field $k=\mathbb{F}_q$. For $N=1,2$ these results provide concrete formulas for $t_N(n)$ and $\bar{t}_N(n)$ a

  41. Filippo Bracci, Manuel D. Contreras, Santiago Diaz-Madrigal

    In this paper we prove a formula describing the infinitesimal generator of a continuous semigroup $(\v_t)$ of holomorphic self-maps of the unit disc with respect to a boundary regular fixed point. The result is based on Alexandrov-Clark measures techniques. In particular we prove that the Alexandrov-Clark measure of $(\v_t)$ at a boundary regular fixed point

  42. Mitsuru Sugimoto, Naohito Tomita

    In this paper, we study the boundedness of pseudo-differential operators with symbols in $S_{ρ,δ}^m$ on the modulation spaces $M^{p,q}$. We discuss the order $m$ for the boundedness $\mathrm{Op}(S_{ρ,δ}^m) \subset \calL(M^{p,q}(\R^n))$ to be true. We also prove the existence of a Calderón-Zygmund operator which is not bounded on the modulation space $M^{p,q}

  43. Robert Parviainen

    We introduce weighted succession rules and parametric production matrices - simple extensions of the standard ECO method succession rules and production matrices. The purpose is to enumerate combinatorial objects with respect to several variables. We consider one main example, from the theory of Dyck paths. The path statistics primarily considered are peak h

  44. Stefan A. G. De Wannemacker, David W. Lewis

    In ``New Proofs of the structure theorems for Witt Rings&#39;&#39;, Lewis shows how the standard ring-theoretic results on the Witt ring can be deduced in a quick and elementary way from the fact that the Witt ring of a field is integral and from the specific nature of the explicit annihilating polynomials he provides. We will show in the present article tha

  45. Guan-Yu Chen, Laurent Saloff-Coste

    We study the cutoff phenomenon for generalized riffle shuffles where, at each step, the deck of cards is cut into a random number of packs of multinomial sizes which are then riffled together.

  46. S. Favorov

    We extend the notion of amoeba to holomorphic almost periodic functions in tube domains. In this setting, the order of a function in a connected component of the complement to its amoeba is just the mean motion of this function. We also find a correlation between the orders in different components.

  47. Zach Dietz, Sunder Sethuraman

    We consider finite-state time-nonhomogeneous Markov chains where the probability of moving from state $i$ to state $j\neq i$ at time $n$ is $G(i,j)/n^ζ$ for a ``generator&#39;&#39; matrix $G$ and strength parameter $ζ>0$. In these chains, as time grows, the positions are less and less likely to change, and so form simple models of age-dependent time-reinforc

  48. D. S. Popović, B. Sazdović

    In the present article, we derive the space-time action of the bosonic string in terms of geometrical quantities. First, we study the space-time geometry felt by probe bosonic string moving in antisymmetric and dilaton background fields. We show that the presence of the antisymmetric field leads to the space-time torsion, and the presence of the dilaton fiel

  49. Bartlomiej Czech

    I develop the simplest geometric-discretized analogue of two dimensional scalar field theory, which qualitatively reproduces the trace anomaly of the continuous theory. The discrete analogue provides an interpretation of the trace anomaly in terms of a non-trivial transformation of electric-magnetic duality-invariant modes of resistor networks that accommoda

  50. M. C. Bertin, B. M. Pimentel, P. J. Pompeia

    In this work we analyze systems described by Lagrangians with higher order derivatives in the context of the Hamilton-Jacobi formalism for first order actions. Two different approaches are studied here: the first one is analogous to the description of theories with higher derivatives in the hamiltonian formalism according to [Sov. Phys. Journ. 26 (1983) 730;

  51. Kazuo Hosomichi

    We discuss how the disc correlators of H3+ WZW model are determined in terms of those of Liouville theory.

  52. Tamar T. Khachidze, Anzor A. Khelashvili

    We propose a symmetry of the Dirac equation under the interchange of signs of eigenvalues of the Dirac&#39;s $K$ operator. We show that the only potential which obeys this requirement is the Coulomb one for both vector and scalar cases. Spectrum of the Dirac Equation is obtained algebraically for arbitrary combination of Lorentz-scalar and Lorentz-vector Cou

  53. Vladimir B. Kopeliovich, Andrei M. Shunderuk

    The extention of the chiral soliton approach to hypernuclei - strange or heavy flavoured - becomes more reliable due to success in describing of other properties of nuclei, e.g. the symmetry energy of nuclei with atomic numbers up to ~30. The binding energies of the ground states of light hypernuclei with strangeness S=-1 have been described in qualitative a

  54. T. Barnes

    In this paper we summarize our recent results for low energy associated charmonium production cross sections, using 1) crossing symmetry, and 2) an explicit hadronic model. These predictions are of relevance to the planned charmonium and charmonium hybrid production experiment PANDA at GSI.

  55. Jose L. Goity, Chandana P. Jayalath

    The contributions to heavy meson mass differences by the strong hyperfine interaction, the light quark masses and the electromagnetic interaction are obtained from the empirical values of the $D$, $D^*$, $B$ and $B^*$ masses by means of a mass formula based on the heavy quark mass expansion. The three different types of contributions are determined with sign

  56. Jose L. Goity Norberto N. Scoccola

    We analyze the photo-production helicity amplitudes for the positive parity excited baryons in the context of the $1/N_c$ expansion of QCD. The results show that sub-leading corrections in $1/N_c$ are important and that, while 1-body effective operators are dominant, there is some evidence for the need of 2-body effects.

  57. Wenna Xu, Xuelei Wang, Zhen-jun Xiao

    In the topcolor-assistant technicolor (TC2) model, the typical physical particles, top-pions and top-Higgs, are predicted and the existence of these particles could be regarded as the robust evidence of the model. These particles are accessible at the Tevatron and LHC, and furthermore the flavor-changing(FC) feature of the TC2 model can provide us a unique c

  58. Johan Bijnens, Joaquim Prades

    We review the present status of the hadronic light-by-light contribution to muon g-2 and critically compare recent calculations.

  59. Michael Strickland

    Despite the apparent success of ideal hydrodynamics in describing the elliptic flow data which have been produced at Brookhaven National Lab&#39;s Relativistic Heavy Ion Collider, one lingering question remains: is the use of ideal hydrodynamics at times t < 1 fm/c justified? In order to justify its use a method for rapidly producing isotropic thermal matter

  60. Simon Turbide, Charles Gale

    We discuss the emission of high momentum lepton pairs (p_T>4 GeV) with low invariant masses (M << p_T) in central Au+Au collisions at RHIC (\sqrt{s_{NN}}=200 GeV). The spectra of dileptons produced through interactions of quark and antiquark jets with the quark-gluon plasma (QGP) have been calculated. Annihilation and Compton scattering processes, as well as

  61. A. Ohnishi, N. Kawamoto, K. Miura

    We study the phase diagram of quark matter at finite temperature (T) and chemical potential (mu) in the strong coupling region of lattice QCD for color SU(3). Baryon has effects to extend the hadron phase to a larger mu direction relative to Tc at low temperatures in the strong coupling limit. With the 1/g^2 corrections, Tc is found to decrease rapidly as g

  62. Gianluca Lamanna

    The NA48/2 has collected the largest amount of $K\to3 π$. The charge asymmetry parameter $A_g$, sensitive to CP violation effects, has been measured with a precision of $10^{-4}$ (preliminary) both in the three charged pion mode (&#34;charged&#34; mode) and in the mode with two neutral pions in the final state (&#34;neutral&#34; mode). The Dalitz plot struct

  63. K. Somiya, Y. Chen, S. Kawamura, N. Mio

    The sensitivity of next-generation gravitational-wave detectors such as Advanced LIGO and LCGT should be limited mostly by quantum noise with an expected technical progress to reduce seismic noise and thermal noise. Those detectors will employ the optical configuration of resonant-sideband-extraction that can be realized with a signal-recycling mirror added

  64. Nurettin Pirinççioglu, Ilker Sert

    We explore differences between scalar field, and scalar density solutions by using Robertson-Walker (RW) metric, and also a non-relativistic Hamiltonian is derived for a scalar density field in the post-Newtonian approximation. The results are compared with those of scalar field. The expanding universe in RW metric, and post-Newtonian solution of Klein-Gordo

  65. Leszek M. Sokołowski

    In my lectures I will deal with three seemingly unrelated problems: i) to what extent is general relativity exceptional among metric gravity theories? ii) is it possible to define gravitational energy density applying field-theory approach to gravity? and iii) can a consistent theory of a gravitationally interacting spin-two field be developed at all? The co

  66. Shun-Jin Wang

    The similarity between the energy spectra of relativistic particles and that of quasi-particles in super-conductivity BCS theory makes us conjecture that the relativistic physical vacuum medium as the ground state of the background field is a super fluid medium, and the rest mass of a relativistic particle is like the energy gap of a quasi-particle. This con

  67. Avery E. Broderick, Ramesh Narayan

    The gravastar model, which postulates a strongly correlated thin shell of anisotropic matter surrounding a region of anti-de Sitter space, has been proposed as an alternative to black holes. We discuss constraints that present-day observations of well-known black hole candidates place on this model. We focus upon two black hole candidates known to have extra

  68. Wayne Eberly, Mark Giesbrecht, Pascal Giorgi, Arne Storjohann

    Block projections have been used, in [Eberly et al. 2006], to obtain an efficient algorithm to find solutions for sparse systems of linear equations. A bound of softO(n^(2.5)) machine operations is obtained assuming that the input matrix can be multiplied by a vector with constant-sized entries in softO(n) machine operations. Unfortunately, the correctness o

  69. Gilles Villard

    Given a lattice basis of n vectors in Z^n, we propose an algorithm using 12n^3+O(n^2) floating point operations for checking whether the basis is LLL-reduced. If the basis is reduced then the algorithm will hopefully answer &#39;&#39;yes&#39;&#39;. If the basis is not reduced, or if the precision used is not sufficient with respect to n, and to the numerical

  70. Andras Vanyolos, Balazs Dora, Attila Virosztek

    We present a mean-field theoretical study on the effect of a single non-magnetic impurity in quasi-one dimensional unconventional density wave. The local scattering potential is treated within the self-consistent $T$-matrix approximation. The local density of states around the impurity shows the presence of resonant states in the vicinity of the Fermi level,

  71. Isaak D. Mayergoyz, Zhenyu Zhang, Giovanni Miano

    A novel theoretical approach to the dynamics analysis of excitation of plasmon modes in nanoparticles is presented. This approach is based on the biorthogonal plasmon mode expansion and it leads to the predictions of time-dynamics of excitation of specific plasmon modes as well as their steady state amplitude and their decay. Temporal characteristics of plas

  72. Vasili Perebeinos, Phaedon Avouris

    We calculate the optical properties of carbon nanotubes in an external static electric field directed along the tube axis. We predict strong Franz-Keldysh oscillations in the first and second band-to-band absorption peaks, quadratic Stark effect of the first two excitons, and the field dependence of the bound exciton ionization rate for a wide range of tube

  73. Eugene V. Sukhorukov, Andrew N. Jordan, Simon Gustavsson, Renaud Leturcq

    Interactions between nanoscale semiconductor structures form the basis for charge detectors in the solid state. Recent experimental advances have demonstrated the on-chip detection of single electron transport through a quantum dot (QD). The discreteness of charge in units of e leads to intrinsic fluctuations in the electrical current, known as shot noise. T

  74. Fei Lin, Erik S. Sørensen, Catherine Kallin, A. John Berlinsky

    The smallest fullerene, dodecahedral C20, is studied using a one band Hubbard model parameterized by U/t. Results are obtained using exact diagonalization of matrices with linear dimensions as large as 5.7 x 10^9, supplemented by quantum Monte Carlo. We report the magnetic and spectral properties of C20 as a function of U/t and investigate electronic pair bi

  75. W. Zhang, M. A. Zudov, L. N. Pfeiffer, K. W. West

    We report on magnetotransport measurements in a high-mobility two-dimentional electron system subject simultaneously to AC (microwave) and DC (Hall) fields. We find that DC excitation affects microwave photoresistance in a nontrivial way. Photoresistance maxima (minima) evolve into minima (maxima) and back, reflecting strong coupling and interplay of AC- and

  76. C. Dotti, A. Gambassi, M. N. Popescu, S. Dietrich

    We study a lattice model for the spreading of fluid films, which are a few molecular layers thick, in narrow channels with inert lateral walls. We focus on systems connected to two particle reservoirs at different chemical potentials, considering an attractive substrate potential at the bottom, confining side walls, and hard-core repulsive fluid-fluid intera

  77. C. Kurter, D. Mazur, L. Ozyuzer, D. G. Hinks

    Interlayer tunneling spectroscopy measurements were performed on mesa arrays of Bi-2212 single crystals, intercalated with HgBr$_2$. Tunneling conductances were obtained over a wide temperature range to examine the spectral features, especially the behavior of the quasiparticle peaks corresponding to superconducting energy gaps (SGs). Experimental spectra sh

  78. M. R. Norman

    Linear response theory, commonly known as the random phase approximation (RPA), predicts a rich magnetic excitation spectrum for d-wave superconductors. Many of the features predicted by such calculations appear to be reflected in inelastic neutron scattering data of the cuprates. In this article, I will present results from RPA calculations whose input is b

  79. Reinhold Kleiner, Dieter Koelle, John Clarke

    We investigate rf SQUIDs (Superconducting QUantum Interference Devices), coupled to a resonant input circuit, a readout tank circuit and a preamplifier, by numerically solving the corresponding Langevin equations and optimizing model parameters with respect to noise temperature. We also give approximate analytic solutions for the noise temperature, which we

  80. Reinhold Kleiner, Dieter Koelle, John Clarke

    We investigate the characteristics and noise performance of rf Superconducting Quantum Interference Devices (SQUIDs) by solving the corresponding Langevin equations numerically and optimizing the model parameters with respect to noise energy. After introducing the basic concepts of the numerical simulations, we give a detailed discussion of the performance o

  81. Ying-Yuan Zhou, Yong-Jin Cho, Zhiguo Ge, Xinyu Liu

    We present a detailed investigation of exchange-dominated nonpropagating spin-wave modes in a series of 100 nm Ga$_{1 - x}$Mn$_{x}$As films with Mn concentrations $x$ ranging from 0.02 to 0.08. The angular and Mn concentration dependences of spin wave resonance modes have been studied for both as-grown and annealed samples. Our results indicate that the magn

  82. Mykola Tasinkevych, Denis Andrienko

    Three-body effective interactions emerging between parallel cylindrical rods immersed in a nematic liquid crystals are calculated within the Landau-de Gennes free energy description. Collinear, equilateral and midplane configurations of the three colloidal particles are considered. In the last two cases the effective triplet interaction is of the same magnit

  83. Balázs Dóra, Peter Thalmeier

    We have studied the electric and thermal response of two-dimensional Dirac-fermions in a quantizing magnetic field in the presence of localized disorder. The electric and heat current operators in the presence of magnetic field are derived. The self-energy due to impurities is calculated self-consistently, and depends strongly on the frequency and field stre

  84. G. Malpuech, D. D. Solnyshkov, H. Ouerdane, M. M. Glazov

    We report the calculation of cavity exciton-polariton phase diagram which takes into account the presence of realistic structural disorder. Polaritons are modelled as weakly interacting two-dimensional bosons. We show that with increasing density polaritons first undergo a quasi-phase transition towards a Bose glass: the condensate is localized in at least o

  85. C. Pennetta, E. Alfinito, L. Reggiani

    We introduce a multi-species network model which describes the resistance fluctuations of a resistor in a non-equilibrium stationary state. More precisely, a thin resistor characterized by a 1/f^alpha resistance noise is described as a two-dimensional network made by different species of elementary resistors. The resistor species are distinguished by their r

  86. C. J. van der Beek, Thierry Klein, René Brusetti, Christophe Marcenat

    Specific heat measurements show that the introduction of amorphous columnar defects considerably affects the transition from the normal to the superconducting state in zero magnetic field. Experimental results are compared to numerical simulations of the 3D XY model for both the pure system and the system containing random columnar disorder. The numerics rep

  87. V. Lovchinov, A. Apostolov, D. Dimitrov, I. Radulov

    Rare-earth manganites are fascinating, because they display a wide variety of fundamental properties from magnetism to ferroelectricity, from colossal magnetoresistance to semi-metallicity, and because they can be used in a number of important technological applications such as controlling a magnetic memory by an electric field or vice versa, new types of at

  88. D. Dimitrov, I. Radulov, V. Lovchinov, A. Apostolov

    Compounds with distorted perovskite structure of the 4-f and 3-d transition metals with the common formula LnTO3 (where Ln is rare-earth element, T is an element from the Fe group) are the most multifold binary oxides of these two groups elements. Wide range of stability for this structure allows the realization of combinations of the Lanthanides with all th

  89. Srutarshi Pradhan, Per C. Hemmer

    Under an applied external load the global load-sharing fiber bundle model, with individual fiber strength thresholds sampled randomly from a probability distribution, will relax to an equilibrium state, or to complete bundle breakdown. The relaxation can be viewed as taking place in a sequence of steps. In the first step all fibers weaker than the applied st

  90. Ender Akcöltekin, Thorsten Peters, Ralf Meyer, Andreas Duvenbeck

    In the challenging search for tools that are able to modify surfaces on the nanometer scale, heavy ions with energies of several 10 MeV are becoming more and more attractive. In contrast to slow ions where nuclear stopping is important and the energy is dissipated into a large volume in the crystal, in the high energy regime the stopping is due to electronic

  91. Nayoung Lee, Han-Yong Choi, Hyeonjin Doh, K. Char

    We calculate the superconducting critical temperature $T_c$, the singlet pair function $Ψ^+(x)$, and triplet pair function $Ψ^-(x)$ of superconductor/normal metal/ferromagnet (S/N/F) trilayers using the linearized Usadel equation near $T_c$. The Green&#39;s function method developed by Fominov $et al.$ for the S/F bilayers is extended to the S/N/F trilayer s

  92. Reinhard K. Kremer, Jun Sung Kim, Arndt Simon

    We review the characteristics of some carbon based novel superconductors which emerged in the past two decades since the discovery of superconductivity in the high-T_c oxocuprates. In particular, we summarize the properties of ternary layered carbide halides of the rare rarth metals with composition RE2C2X2 (RE = Y, La; X=Cl, Br, I) and of the rare earth di-

  93. Shun-Qing Shen

    This is a reply to W. Zawadzki&#39;s paper (arXiv: cond-mat/0701378) on non-exietence of spin transverse force for a relativistic electron. The force was first proposed by the present author that the spin current will experience a transverse force in an electric field as a relativistic quantum mechanical effect, and in semiconductor with Rahsba spin-orbit co

  94. Cecile Monthus, Thomas Garel

    We consider the model of the directed polymer in a random medium of dimension 1+3, and investigate its multifractal properties at the localization/delocalization transition. In close analogy with models of the quantum Anderson localization transition, where the multifractality of critical wavefunctions is well established, we analyse the statistics of the po

  95. Ol&#39;ga Dimitrova, M. V. Feigel&#39;man

    A detailed theory of a phase diagram of a 2D surface superconductor in a parallel magnetic field is presented. A spin-orbital interaction of the Rashba type is known to produce at a high magnetic field $h$ (and in the absence of impurities) an inhomogeneous superconductive phase similar to the Larkin-Ovchinnikov-Fulde-Ferrel (LOFF) state with an order parame

  96. J. C. Li

    The object of this article is to review the development of ultrahigh-density, nanoscale data storage, i.e., nanostorage. As a fundamentally new type of storage system, the recording mechanisms of nanostorage may be completely different to those of the traditional devices. Currently, two types of molecules are being studied for potential application in nanost

  97. A. Muñoz Mateo, V. Delgado

    By incorporating the zero-point energy contribution we derive simple and accurate extensions of the usual Thomas-Fermi (TF) expressions for the ground-state properties of trapped Bose-Einstein condensates that remain valid for an arbitrary number of atoms in the mean-field regime. Specifically, we obtain approximate analytical expressions for the ground-stat

  98. I. Iwata, K. Ohta, N. Tamura, M. Akiyama

    (abridged) We report the UV luminosity function (LF) of Lyman break galaxies at z~5 derived from a deep and wide survey using the Subaru/Suprime-Cam. Target fields consist of two blank regions of the sky (the HDF-N and J0053+1234), and the total effective surveyed area is 1290 sqarcmin. Applications of carefully determined colour selection criteria in V-I an

  99. C. Leipski, M. Haas, H. Meusinger, R. Siebenmorgen

    Context: A long-standing challenge of observational AGN research is to find type 2 quasars, the luminous analogues of Seyfert-2 galaxies. Aims: We search for luminous narrow-line type 2 AGN, characterise their properties, and compare them with broad-line type 1 AGN. Methods: Combining the ISOCAM parallel survey at 6.7 mu with 2MASS, we have selected AGN via

  100. H. K. C. Yee, M. D. Gladders, D. G. Gilbank, S. Majumdar

    The Red-Sequence Cluster Surveys (RCS-1 and RCS-2) are large optical imaging surveys optimized to create well-characterized catalogs of clusters of galaxies up to a redshift of ~1. We describe our first cosmological analysis, using the self-calibration technique, of a cluster sample of ~1000 from the 90 sq. deg RCS-1, using optical richness as a mass proxy.