Results for "M. Franke"

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Survival probability of an immobile target surrounded by mobile trapsMar 13 2012Jun 11 2012We study analytically, in one dimension, the survival probability $P_{s}(t)$ up to time $t$ of an immobile target surrounded by mutually noninteracting traps each performing a continuous-time random walk (CTRW) in continuous space. We consider a general ... More
Gate-controlled quantum dots and superconductivity in planar germaniumJan 26 2018Superconductors and semiconductors are crucial platforms in the field of quantum computing. They can be combined to hybrids, bringing together physical properties that enable the discovery of new emergent phenomena and provide novel strategies for quantum ... More
Ballistic supercurrent discretization and micrometer-long Josephson coupling in germaniumAug 02 2018We fabricate Josephson field-effect-transistors in germanium quantum wells contacted by superconducting aluminum and demonstrate supercurrents carried by holes that extend over junction lengths of several micrometers. In superconducting quantum point ... More
Every Binary Code Can Be Realized by Convex SetsNov 08 2017Apr 27 2018Much work has been done to identify which binary codes can be represented by collections of open convex or closed convex sets. While not all binary codes can be realized by such sets, here we prove that every binary code can be realized by convex sets ... More
Local Fields without Restrictions on the Spectrum of 4-Momentum Operator and Relativistic Lindblad EquationAug 17 2009Quantum theory of Lorentz invariant local scalar fields without restrictions on 4-momentum spectrum is considered. The mass spectrum may be both discrete and continues and the square of mass as well as the energy may be positive or negative. Such fields ... More
Spin lifetime and charge noise in hot silicon quantum dot qubitsMar 05 2018Sep 01 2018We investigate the magnetic field and temperature dependence of the single-electron spin lifetime in silicon quantum dots and find a lifetime of 2.8 ms at a temperature of 1.1 K. We develop a model based on spin-valley mixing and find that Johnson noise ... More
Correlating Paleoclimate Time Series: Sources of Uncertainty and Potential PitfallsMar 28 2019Comparing paleoclimate time series is complicated by a variety of typical features, including irregular sampling, age model uncertainty (e.g., errors due to interpolation between radiocarbon sampling points) and time uncertainty (uncertainty in calibration), ... More
Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)3(boaDTDA)]n (Ln=Sm, La) using implanted muonsMay 13 2019We present the results of muon-spin relaxation ($\mu^{+}$SR) measurements on antiferromagnetic and ferromagnetic spin chains. In antiferromagnetic CuF$_{2}$(pyz) we identify a transition to long range magnetic order taking place at $T_{\mathrm{N}} = 0.6(1)$ ... More
Exploiting boundary states of imperfect spin chains for high-fidelity state transferDec 19 2011Feb 14 2012We study transfer of a quantum state through XX spin chains with static imperfections. We combine the two standard approaches for state transfer based on (i) modulated couplings between neighboring spins throughout the spin chain and (ii) weak coupling ... More
Capillary micromechanics: Measuring the elasticity of microscopic soft objectsAug 31 2012We present a simple method for accessing the elastic properties of microscopic deformable particles. This method is based on measuring the pressure-induced deformation of soft particles as they are forced through a tapered glass microcapillary. It allows ... More
Angular EPR paradoxJun 28 2005The violation of local uncertainty relations is a valuable tool for detecting entanglement, especially in multi-dimensional systems. The orbital angular momentum of light provides such a multi-dimensional system. We study quantum correlations for the ... More
A Bernstein Inequality For Spatial Lattice ProcessesFeb 07 2017Dec 05 2017In this article we present a Bernstein inequality for sums of random variables which are defined on a spatial lattice structure. The inequality can be used to derive concentration inequalities. It can be useful to obtain consistency properties for nonparametric ... More
QED(1+1) on the Light Front and its implications for semiphenomenological methods in QCD(3+1)Oct 13 2006A possibility of semiphenomenological description of vacuum effects in QCD quantized on the Light Front (LF) is discussed. A modification of the canonical LF Hamiltonian for QCD is proposed, basing on the detailed study of the exact description of vacuum ... More
Piecewise excluding geodesic languagesMay 03 2017The complexity of a geodesic language has connections to algebraic properties of the group. Gilman, Hermiller, Holt, and Rees show that a finitely generated group is virtually free if and only if its geodesic language is locally excluding for some finite ... More
A functional non-central limit theorem for jump-diffusions with periodic coefficients driven by stable Levy-noiseNov 28 2006We prove a functional non-central limit theorem for jump-diffusions with periodic coefficients driven by strictly stable Levy-processes with stability index bigger than one. The limit process turns out to be a strictly stable Levy process with an averaged ... More
Hybrid density-functional theory calculations of electronic and optical properties of mercaptocarboxylic acids on ZnO $(10{\overline 1}0)$ surfacesOct 04 2018In this work we investigate the electronic properties of mercaptocarboxylic acids with several carbon chain lengths adsorbed on ZnO-(10-10) surfaces via density functional theory calculations using semi-local and hybrid exchange-correlation functionals. ... More
Correction to: The scaling limit behaviour of periodic stable-like processesAug 31 2007Correction to Bernoulli (2006), 12, 551--570
Induction of a photostationary ring-opening/closing state of spiropyran monolayers on the semi-metallic Bi(110) surfaceSep 25 2012Molecular switches on metal surfaces typically show very little photoreactivity. Using scanning tunneling microscopy we show that the ring-opening/-closing switch nitrospiropyran thermally and optically isomerizes to the open merocyanine form on a Bi(110) ... More
Bounds and optimisation of orbital angular momentum bandwidths within parametric down-conversion systemsDec 16 2011Aug 01 2012The measurement of high-dimensional entangled states of orbital angular momentum prepared by spontaneous parametric down-conversion can be considered in two separate stages: a generation stage and a detection stage. Given a certain number of generated ... More
Increasing the dimension in high-dimensional two-photon orbital angular momentum entanglementMay 09 2012Any practical experiment utilising the innate D-dimensional entanglement of the orbital angular momentum (OAM) state space of photons is subject to the modal capacity of the detection system. We show that given such a constraint, the number of measured, ... More
Quantitative analyses of empirical fitness landscapesFeb 20 2012Oct 17 2012The concept of a fitness landscape is a powerful metaphor that offers insight into various aspects of evolutionary processes and guidance for the study of evolution. Until recently, empirical evidence on the ruggedness of these landscapes was lacking, ... More
Evolutionary accessibility of mutational pathwaysMar 12 2011Aug 29 2011Functional effects of different mutations are known to combine to the total effect in highly nontrivial ways. For the trait under evolutionary selection (`fitness'), measured values over all possible combinations of a set of mutations yield a fitness ... More
Measurements of the Lifetime of Orthopositronium in the LAB-Based Liquid Scintillator of JUNOApr 25 2018Electron antineutrinos are detected in organic liquid scintillator based neutrino experiments by means of the inverse beta decay, producing both a positron and a neutron. The positron may form a bound state together with an electron, called positronium ... More
Quantum Formulation of Fractional Orbital Angular MomentumNov 15 2006The quantum theory of rotation angles (S. M. Barnett and D. T. Pegg, Phys. Rev. A, 41, 3427-3425 (1990)) is generalised to non-integer values of the orbital angular momentum. This requires the introduction of an additional parameter, the orientation of ... More
Spin-dependent recombination involving oxygen-vacancy complexes in siliconFeb 24 2014Feb 26 2014Spin-dependent relaxation and recombination processes in $\gamma$-irradiated $n$-type Czochralski-grown silicon are studied using continuous wave (cw) and pulsed electrically detected magnetic resonance (EDMR). Two processes involving the SL1 center, ... More
Construction of Perturbatively Correct Light Front Hamiltonian for (2+1)-Dimensional Gauge TheorySep 23 2016In this paper we consider (2+1)-dimensional SU(N)-symmetric gauge theory within light front perturbation theory, regularized by the method analogous to Pauli-Villars regularization. This enables us to construct correct renormalized light front Hamiltonian. ... More
Rent's rule and extensibility in quantum computingJun 06 2018Quantum computing is on the verge of a transition from fundamental research to practical applications. Yet, to make the step to large-scale quantum computation, an extensible qubit system has to be developed. In classical semiconductor technology, this ... More
Discrete relaxation of exciton-polaritons in an inhomogeneous potentialJan 12 2015We present indications, that the wave function-stiffness condition during energy-relaxation as observed in single-phase state quantum systems manifests also in a single particle ensemble. This is demonstrated for exciton-polaritons in the strong coupling ... More
Spatially dependent electromagnetically induced transparencyDec 03 2014Recent years have seen vast progress in the generation and detection of structured light, with potential applications in high capacity optical data storage and continuous variable quantum technologies. Here we measure the transmission of structured light ... More
Fast two-qubit logic with holes in germaniumApr 25 2019The promise of quantum computation with quantum dots has stimulated widespread research. Still, a platform that can combine excellent control with fast and high-fidelity operation is absent. Here, we show single and two-qubit operations based on holes ... More
Quantum Fields on the Light Front, Formulation in Coordinates close to the Light Front, Lattice ApproximationOct 01 2006We review the fundamental ideas of quantizing a theory on a Light Front including the Hamiltonian approach to the problem of bound states on the Light Front and the limiting transition from formulating a theory in Lorentzian coordinates (where the quantization ... More
Multiple-quantum transitions and charge-induced decoherence of donor nuclear spins in siliconOct 13 2016We study single- and multi-quantum transitions of the nuclear spins of ionized arsenic donors in silicon and find quadrupolar effects on the coherence times, which we link to fluctuating electrical field gradients present after the application of light ... More
Quadrupolar Effects on Nuclear Spins of Neutral Arsenic Donors in SiliconMar 04 2016We present electrically detected electron nuclear double resonance measurements of the nuclear spins of ionized and neutral arsenic donors in strained silicon. In addition to a reduction of the hyperfine coupling, we find significant quadrupole interactions ... More
Large-uncertainty intelligent states for angular momentum and angleJun 28 2005Oct 20 2005The equality in the uncertainty principle for linear momentum and position is obtained for states which also minimize the uncertainty product. However, in the uncertainty relation for angular momentum and angular position both sides of the inequality ... More
Entangled topological features of lightAug 26 2010We report the entanglement of topological features, namely, isolated, linked optical vortex loops in the light from spontaneous parametric down-conversion (SPDC). In three dimensions, optical vortices are lines of phase singularity and vortices of energy ... More
The Convergence rate of the Gibbs sampler for the $2-$D Ising model via a geometric boundApr 24 2018May 23 2018We study the geometric bound introduced by Diaconis and Stroock $(1991)$ of the Gibbs sampler for the two-dimensional Ising model with free boundary condition. The obtained result generalizes the method proposed by Shiu and Chen $(2015)$ from dimension ... More
Interaction of Strain and Nuclear Spins in Silicon: Quadrupolar Effects on Ionized DonorsFeb 28 2015Apr 07 2016The nuclear spins of ionized donors in silicon have become an interesting quantum resource due to their very long coherence times. Their perfect isolation, however, comes at a price, since the absence of the donor electron makes the nuclear spin difficult ... More
Adsorption induced pyramidal distortion of the tri-metallic nitride core inside the endohedral fullerene Sc$_3$N@C$_{80}$ on the Ag(111) surfaceMar 13 2019Our ability to understand and tailor metal-organic interfaces is mandatory to functionalize organic complexes for next generation electronic and spintronic devices. For magnetic data storage applications, metal-carrying organic molecules, so called single ... More
Smart Transformations: The Evolution of Choice PrinciplesApr 30 2015Evolutionary game theory classically investigates which behavioral patterns are evolutionarily successful in a single game. More recently, a number of contributions have studied the evolution of preferences instead: which subjective conceptualizations ... More
CosMO - A Cosmic Muon Observer Experiment for StudentsSep 13 2013What are cosmic particles and where do they come from? These are questions which are not only fascinating for scientists in astrophysics. With the CosMO experiment (Cosmic Muon Observer) students can autonomously study these particles. They can perform ... More
Critical-point model dielectric function analysis of WO$_3$ thin films deposited by atomic layer deposition techniquesMay 08 2018WO3 thin films were grown by atomic layer deposition and spectroscopic ellipsometry data gathered in the photon energy range of 0.72-8.5 eV and from multiple samples was utilized to determine the frequency dependent complex-valued isotropic dielectric ... More
Evolutionary accessibility in tunably rugged fitness landscapesMar 22 2012Oct 17 2012The adaptive evolution of a population under the influence of mutation and selection is strongly influenced by the structure of the underlying fitness landscape, which encodes the interactions between mutations at different genetic loci. Theoretical studies ... More
A self-similar process arising from a random walk with random environment in random sceneryFeb 25 2011In this article, we merge celebrated results of Kesten and Spitzer [Z. Wahrsch. Verw. Gebiete 50 (1979) 5-25] and Kawazu and Kesten [J. Stat. Phys. 37 (1984) 561-575]. A random walk performs a motion in an i.i.d. environment and observes an i.i.d. scenery ... More
A duality approach to the worst case value at risk for a sum of dependent random variables with known covariancesDec 09 2009We propose an approach to the aggregation of risks which is based on estimation of simple quantities (such as covariances) associated to a vector of dependent random variables, and which avoids the use of parametric families of copulae. Our main result ... More
Photon Acceleration in a Flying FocusApr 30 2019A high-intensity laser pulse propagating through a medium triggers an ionization front that can accelerate and frequency-upshift the photons of a second pulse. The maximum upshift is ultimately limited by the accelerated photons outpacing the ionization ... More
Spin Selection Rule-Based Sub-Millisecond Hyperpolarization of Nuclear Spins in SiliconAug 16 2013In this work, we devise a fast and effective nuclear spin hyperpolarization scheme, which is in principle magnetic field and temperature independent. We use this scheme to experimentally demonstrate polarizations of up to 66% for phosphorus donor nuclear ... More
Slanted Stixels: Representing San Francisco's Steepest StreetsJul 17 2017In this work we present a novel compact scene representation based on Stixels that infers geometric and semantic information. Our approach overcomes the previous rather restrictive geometric assumptions for Stixels by introducing a novel depth model to ... More
Measurement of a false electric dipole moment signal from $^{199}$Hg atoms exposed to an inhomogeneous magnetic fieldMar 30 2015Aug 03 2015We report on the measurement of a Larmor frequency shift proportional to the electric-field strength for $^{199}{\rm Hg}$ atoms contained in a volume permeated with aligned magnetic and electric fields. This shift arises from the interplay between the ... More
Determination of measurement uncertainty by simulationJul 04 2017Sep 08 2017Modern coordinate measurement machines (CMM) are universal tools to measure geometric features of complex three-dimensional workpieces. To use them as reliable means of quality control, the suitability of the device for the specific measurement task has ... More
Exploring a proximity-coupled Co chain on Pb(110) as a possible Majorana platformApr 19 2017Linear, suspended chains of magnetic atoms proximity coupled to an s-wave superconductor are predicted to host Majorana zero modes at the chain ends in the presence of strong spin-orbit coupling. Specifically, iron (Fe) chains on Pb(110) have been explored ... More
The Asymptotic Covariance Matrix of the Odds Ratio Parameter Estimator in Semiparametric Log-bilinear Odds Ratio ModelsMay 04 2011Apr 13 2012The association between two random variables is often of primary interest in statistical research. In this paper semiparametric models for the association between random vectors X and Y are considered which leave the marginal distributions arbitrary. ... More
Theory and limits of on-demand single photon sources using plasmonic resonators: a quantized quasinormal mode approachApr 05 2019Quantum emitters coupled to plasmonic resonators are known to allow enhanced broadband Purcell factors, and such systems have been recently suggested as possible candidates for on-demand single photon sources, with fast operation speeds. However, a true ... More
Correlation of Vibrational Excitations and Electronic Structure\\ with Submolecular ResolutionMar 04 2019The detection of vibrational excitations of individual molecules on surfaces by scanning tunneling spectroscopy does not obey strict selection rules but rather propensity rules. The experimental verification of these is challenging because it requires ... More
Electronic Structure of an Iron-Porphyrin Derivative on Au(111)Nov 25 2018Surface-bound porphyrins are promising candidates for molecular switches, electronics and spintronics. Here, we studied the structural and the electronic properties of Fe-tetra-pyridil-porphyrin adsorbed on Au(111) in the monolayer regime. We combined ... More
Visualizing Intramolecular Distortions as the Origin of Transverse Magnetic AnisotropyOct 31 2018The magnetic properties of metal-organic complexes are strongly influenced by conformational changes in the ligand. The flexibility of Fe-tetra-pyridyl-porphyrin molecules leads to different adsorption configurations on a Au(111) surface. By combining ... More
Influence of magnetic field and ferromagnetic film thickness on domain pattern transfer in multiferroic heterostructuresMar 21 2017Domains in BaTiO$_3$ induces a regular modulation of uniaxial magnetic anisotropy in CoFeB via an inverse magnetostriction effect. As a result, the domain structures of the CoFeB wedge film and BaTiO$_3$ substrate correlate fully and straight ferroelectric ... More
Spin-dependent recombination at arsenic donors in ion-implanted siliconJul 21 2014Spin-dependent transport processes in thin near-surface doping regions created by low energy ion implantation of arsenic in silicon are detected by two methods, spin-dependent recombination (SDR) using microwave photoconductivity and electrically detected ... More
Testing isotropy of the universe using the Ramsey resonance technique on ultracold neutron spinsSep 30 2010Physics at the Planck scale could be revealed by looking for tiny violations of fundamental symmetries in low energy experiments. In 2008, a sensitive test of the isotropy of the Universe using has been performed with stored ultracold neutrons (UCN), ... More
A beamline for fundamental neutron physics at TRIUMFOct 01 2018Dec 26 2018This article describes the new primary proton beamline 1U at TRIUMF. The purpose of this beamline is to produce ultracold neutrons (UCN) for fundamental-physics experiments. It delivers up to 40 microA of 480 MeV protons from the TRIUMF cyclotron to a ... More
Improved X-ray detection and particle identification with avalanche photodiodesMay 26 2015Avalanche photodiodes are commonly used as detectors for low energy x-rays. In this work we report on a fitting technique used to account for different detector responses resulting from photo absorption in the various APD layers. The use of this technique ... More
Electron nuclear double resonance with donor-bound excitons in siliconAug 09 2016Nov 29 2016We present Auger-electron-detected magnetic resonance (AEDMR) experiments on phosphorus donors in silicon, where the selective optical generation of donor-bound excitons is used for the electrical detection of the electron spin state. Because of the long ... More
Network modularity in the presence of covariatesMar 03 2016We characterize the large-sample properties of network modularity in the presence of covariates, under a natural and flexible nonparametric null model. This provides for the first time an objective measure of whether or not a particular value of modularity ... More
Self-assembly of tetracyanonaphtho-quinodimethane (TNAP) based metal-organic networks on Pb(111): Structural, electronic, and magnetic propertiesApr 22 2016We use scanning tunneling microscopy and spectroscopy to investigate structural and electronic properties of tetracyanonaphtho-quinodimethane (TNAP) based metal-organic networks on a superconducting Pb(111) surface. At low temperatures, the TNAP molecules ... More
A residual-based bootstrap for functional autoregressionsMay 18 2019We consider the residual-based or naive bootstrap for functional autoregressions of order 1 and prove that it is asymptotically valid for, e.g., the sample mean and for empirical covariance operator estimates. As a crucial auxiliary result, we also show ... More
Muon spin relaxation investigation of magnetic ordering in the hybrid organic-inorganic perovskites [(CH3)2NH2]M(HCOO)3, M = Ni,Co,Mn,CuJul 07 2010Muon spin relaxation measurements are reported on samples of dimethylammonium metal formates containing magnetic divalent nickel, cobalt, manganese, and copper ions. These hybrid organic-inorganic perovskites exhibit weak ferromagnetism and are, apart ... More
Optical ferris wheel for ultracold atomsNov 15 2006We propose a versatile optical ring lattice suitable for trapping cold and quantum degenerate atomic samples at discrete angular positions. We demonstrate the realisation of intensity patterns generated from Laguerre-Gauss ($\exp(i \ell\theta)$) modes ... More
Ferromagnetic coupling of mononuclear Fe centers in a self-assembled metal-organic network on Au(111)Dec 14 2012The magnetic state and magnetic coupling of individual atoms in nanoscale structures relies on a delicate balance between different interactions with the atomic-scale surrounding. Using scanning tunneling microscopy, we resolve the self-assembled formation ... More
Surfactant-Mediated Growth of Twisted Bilayer Graphene on SiCSep 21 2018We propose a method to grow high-quality twisted bilayer graphene epitaxially on SiC using borazine as a surfactant. With this method, closed layers with a constant orientation with respect to the substrate can be grown over mm-size samples. Using high-resolution ... More
Electron nuclear double resonance with donor-bound excitons in siliconAug 09 2016We measure electron nuclear double resonance (ENDOR) of phosphorus in isotopically purified $^{28}$Si by optical-electrical hybrid detection via the donor-bound exciton transitions. This allows for the control of both nuclear and electron spin of donors ... More
A superfluid helium converter for accumulation and extraction of ultracold neutronsMay 27 2007We report the first successful extraction of accumulated ultracold neutrons (UCN) from a converter of superfluid helium, in which they were produced by downscattering neutrons of a cold beam from the Munich research reactor. Windowless UCN extraction ... More
A fast-switching magnet serving a spallation-driven ultracold neutron sourceMay 21 2019A fast-switching, high-repetition-rate magnet and power supply have been developed for and operated at TRIUMF, to deliver a proton beam to the new ultracold neutron (UCN) facility. The facility possesses unique operational requirements: a time-averaged ... More
Neutralino Mass Bounds in the Next-To-Minimal Supersymmetric Standard ModelAug 02 1994We analyze the experimental data from the search for new particles at LEP 100 and obtain mass bounds for the neutralinos of the Next--To--Minimal Supersymmetric Standard Model (NMSSM). We find that for $\tan\beta \gsim 5.5$ a massless neutralino is still ... More
$^4$He sample probe for combined microwave and dc transport measurementsApr 08 2015Combined microwave and dc electrical transport measurements at low temperatures represent a valuable experimental method in many research areas. In particular, when samples are conventional superconductors, a typical experiment requires a combination ... More
Correlations between record events in sequences of random variables with a linear trendMay 19 2011Sep 23 2011The statistics of records in sequences of independent, identically distributed random variables is a classic subject of study. One of the earliest results concerns the stochastic independence of record events. Recently, records statistics beyond the case ... More
Laser Spectroscopy of Muonic Atoms and IonsSep 12 2016Laser spectroscopy of the Lamb shift (2S-2P energy difference) in light muonic atoms or ions, in which one negative muon $\mu^-$ is bound to a nucleus, has been performed. The measurements yield significantly improved values of the root-mean-square charge ... More
Quadrupole Shift of Nuclear Magnetic Resonance of Donors in Silicon at Low Magnetic FieldJun 12 2015Above megahertz shifts of nuclear magnetic resonance lines of antimony and bismuth donors in silicon are reported. Defects created by ion implantation of the donors are discussed as the source of effective electric field gradients generating these shifts. ... More
Chiral selectivity of amino acid adsorption on chiral surfaces - the case of alanine on PtDec 08 2014We study the binding pattern of the amino acid alanine on the naturally chiral Pt surfaces Pt(531), Pt(321) and Pt(643). These surfaces are all vicinal to the {111} direction but have different local environments of their kink sites and are thus a model ... More
Adsorption and ring-opening of lactide on a chiral metal surface studied by Density Functional TheoryNov 04 2014We study the adsorption and ring-opening of lactide on the naturally chiral metal surface Pt(321)$^S$. Lactide is a precursor for polylactic acid ring-opening polymerization and Pt is a well known catalyst surface. We study here the energetics of the ... More
Ultra high densities of cold atoms in a holographically controlled dark SPOT trapAug 21 2013We demonstrate an atom trap geometry for 87Rb which is capable of producing ultra high atom densities. Reradiation forces, which usually limit high densities, can be avoided in dark spontaneous-force optical traps (dark SPOTs) by sheltering atoms from ... More
Correlations of record events as a test for heavy-tailed distributionsSep 09 2011Jan 06 2012A record is an entry in a time series that is larger or smaller than all previous entries. If the time series consists of independent, identically distributed random variables with a superimposed linear trend, record events are positively (negatively) ... More
Stable Limit Theorem for U-Statistic Processes Indexed by a Random WalkDec 10 2012Mar 03 2015Let (S_n)_{n\in\N} be a Z-valued random walk with increments from the domain of attraction of some \alpha-stable law and let (\xi(i))_{i\in\Z} be a sequence of iid random variables. We want to investigate U-statistics indexed by the random walk S_n, that ... More
Records and sequences of records from random variables with a linear trendAug 09 2010We consider records and sequences of records drawn from discrete time series of the form $X_{n}=Y_{n}+cn$, where the $Y_{n}$ are independent and identically distributed random variables and $c$ is a constant drift. For very small and very large drift ... More
Moiré structure of MoS$_2$ on Au(111): Local structural and electronic propertiesFeb 05 2018Apr 03 2018Monolayer islands of molybdenum disulfide (MoS$_2$) on Au(111) form a characteristic moir\'e structure, leading to locally different stacking sequences at the S-Mo-S-Au interface. Using low-temperature scanning tunneling microscopy (STM) and atomic force ... More
Yu-Shiba-Rusinov states in the charge-density modulated superconductor NbSe2Mar 22 2019At low temperatures, charge-density-wave and superconducting order coexist in the quasi-two-dimensional material 2H-NbSe2. Here, we investigate the Yu-Shiba-Rusinov (YSR) states of individual Fe atoms adsorbed in hollow sites of the terminating Se surface. ... More
Enantioselectivity of (321) chiral noble metal surfaces: A Density Functional Theory study of lactate adsorptionOct 03 2013The adsorption of the chiral molecule lactate on the intrinsically chiral noble metal surfaces Pt(321), Au(321) and Ag(321) is studied by Density Functional Theory calculations. We use the oPBE-vdW functional which includes van der Waals forces on an ... More
Convergence of U-statistics indexed by a random walk to stochastic integrals of a Levy sheetJan 30 2014Aug 24 2014We establish limit theorems for U-statistics indexed by a random walk on Z^d and we express the limit in terms of some Levy sheet Z(s,t). Under some hypotheses, we prove that the limit process is Z(t,t) if the random walk is transient or null-recurrent ... More
Two photon amplitude of partially coherent partially entangled electromagnetic fieldsJul 30 2015The development of efficient protocols for pure and mixed states preparation is challenging task. Most of the theory of quantum information applications has been developed for fully coherent or completely incoherent light. However, in many situations ... More
Robust and Scalable Differentiable Neural Computer for Question AnsweringJul 07 2018Deep learning models are often not easily adaptable to new tasks and require task-specific adjustments. The differentiable neural computer (DNC), a memory-augmented neural network, is designed as a general problem solver which can be used in a wide range ... More
The autoregression bootstrap for kernel estimates of smooth nonlinear functional time seriesNov 15 2018Functional times series have become an integral part of both functional data and time series analysis. This paper deals with the functional autoregressive model of order 1 and the autoregression bootstrap for smooth functions. The regression operator ... More
A Crossbar Network for Silicon Quantum Dot QubitsNov 10 2017The spin states of single electrons in gate-defined quantum dots satisfy crucial requirements for a practical quantum computer. These include extremely long coherence times, high-fidelity quantum operation, and the ability to shuttle electrons as a mechanism ... More
Quadrupole Shift of Nuclear Magnetic Resonance of Donors in Silicon at Low Magnetic FieldJun 12 2015Nov 14 2016Shifts from the expected nuclear magnetic resonance frequencies of antimony and bismuth donors in silicon of greater than a megahertz are observed in electrically detected magnetic resonance spectra. Defects created by ion implantation of the donors are ... More
Adsorption of lactic acid on chiral Pt surfaces - A Density Functional Theory studyDec 14 2012The adsorption of the chiral molecule lactic acid on chiral Pt surfaces is studied by Density Functional Theory calculations. First we study the adsorption of L-lactic acid on the flat Pt(111) surface. Using the oPBE-vdW functional which includes van ... More
Acoustic measurements above a plate carrying Lamb wavesApr 08 2016This article presents a set of acoustic measurements conducted on the Statoil funded Behind Casing Logging Set-Up, designed by SINTEF Petroleum Research to resemble an oil well casing. A set of simple simulations using COMSOL Multiphysics were also conducted ... More
Noninvasiveness and time symmetry of weak measurementsAug 05 2011Mar 04 2013Measurements in classical and quantum physics are described in fundamentally different ways. Nevertheless, one can formally define similar measurement procedures with respect to the disturbance they cause. Obviously, strong measurements, both classical ... More
Size Dependence of Domain Pattern Transfer in Multiferroic HeterostructuresJul 02 2013Jan 16 2014Magnetoelectric coupling in multiferroic heterostructures can produce large lateral modulations of magnetic anisotropy enabling the imprinting of ferroelectric domains into ferromagnetic films. Exchange and magnetostatic interactions within ferromagnetic ... More
Physics Opportunities at mu+mu- Higgs FactoriesFeb 21 2002We update theoretical studies of the physics opportunities presented by mu+mu- Higgs factories. Interesting measurements of the Standard Model Higgs decays into {\bar b}b, tau+tau- and WW* may be possible if the Higgs mass is less than about 160 GeV, ... More
Magnetic phases of skyrmion-hosting GaV$_4$S$_{8-y}$Se$_{y}$ ($y = 0, 2, 4, 8$) probed with muon spectroscopyJun 01 2018Sep 11 2018We present the results of a muon-spin spectroscopy investigation of GaV$_4$S$_{8-y}$Se$_{y}$ with $y=0, 2, 4$ and 8. Zero-field measurements suggest that GaV$_{4}$Se$_{8}$ and GaV$_{4}$S$_{8}$ have distinct magnetic ground states, with the latter material ... More
Statistical Inference, Learning and Models in Big DataSep 09 2015Jan 28 2016The need for new methods to deal with big data is a common theme in most scientific fields, although its definition tends to vary with the context. Statistical ideas are an essential part of this, and as a partial response, a thematic program on statistical ... More
The gradual destruction of magnetism in the superconducting family NaFe(1-x)CoxAsDec 02 2011The interplay and coexistence of superconducting, magnetic and structural order parameters in NaFe{1-x}Co{x}As has been studied using SQUID magnetometry, muon-spin rotation and synchrotron x-ray powder diffraction. Substituting Fe by Co weakens the ordered ... More
Muon capture on light isotopes in Double ChoozDec 23 2015May 17 2016Using the Double Chooz detector, designed to measure the neutrino mixing angle $\theta_{13}$, the products of $\mu^-$ capture on $^{12}$C, $^{13}$C, $^{14}$N and $^{16}$O have been measured. Over a period of 489.5 days, $2.3\times10^6$ stopping cosmic ... More