Results for "M. Pletyukhov"

total 210965took 0.12s
Crossover from diffusive to non-diffusive dynamics in the two-dimensional electron gas with Rashba spin-orbit couplingNov 20 2006Mar 06 2007We present the calculation of the density matrix response function of the two-dimensional electron gas with Rashba spin-orbit interaction, which is applicable in a wide range of parameters covering the diffusive and non-diffusive, the dirty and the clean ... More
Tunable Aharonov-Anandan phase in transport through mesoscopic hole ringsMar 06 2008Apr 18 2008We present a theoretical study of spin-3/2 hole transport through mesoscopic rings, based on the spherical Luttinger model. The quasi-one-dimensional ring is created in a symmetric two-dimensional quantum well by a singular-oscillator potential for the ... More
Screening in the two-dimensional electron gas with spin-orbit couplingJun 09 2005Dec 15 2005We study the interplay between electron-electron interaction and Rashba spin-orbit coupling in the two-dimensional electron gas. Using the random phase approximation we predict new screening properties of the electron gas which result in extension of ... More
On the canonically invariant calculation of Maslov indicesMay 30 2003Jun 18 2003After a short review of various ways to calculate the Maslov index appearing in semiclassical Gutzwiller type trace formulae, we discuss a coordinate-independent and canonically invariant formulation recently proposed by A Sugita (2000, 2001). We give ... More
Screening properties of the two-dimensional electron gas with spin-orbit couplingFeb 01 2006Sep 08 2006We study screening properties of the two-dimensional electron gas with Rashba spin-orbit coupling. Calculating the dielectric function within the random phase approximation, we describe the new features of screening induced by spin-orbit coupling, which ... More
Persistent currents in multicomponent Tomonaga-Luttinger liquid: application to mesoscopic semiconductor ring with spin-orbit interactionJun 08 2004We study persistent currents in semiconductor ballistic rings with spin-orbit Rashba interaction. We use as a working model the multicomponent Tomonaga-Luttinger liquid which arises due to the nonparabolic dispersion relations of electrons in the rings ... More
Charge and spin density response functions of the clean two-dimensional electron gas with Rashba spin-orbit coupling at finite momenta and frequenciesMay 16 2007We analytically evaluate charge and spin density response functions of the clean two-dimensional electron gas with Rashba spin-orbit coupling at finite momenta and frequencies. On the basis of our exact expressions we discuss the accuracy of the long-wavelength ... More
Chiral 1D Floquet topological insulators beyond rotating wave approximationNov 29 2018We study one-dimensional (1D) Floquet topological insulators with chiral symmetry going beyond the standard rotating wave approximation. The occurrence of many anticrossings between Floquet replicas leads to a dramatic extension of phase diagram regions ... More
Nonreciprocity realized with quantum nonlinearityJun 01 2018Jun 08 2018Nonreciprocal devices are a key element for signal routing and noise isolation. Rapid development of quantum technologies has boosted the demand for a new generation of miniaturized and low-loss nonreciprocal components. Here we use a pair of tunable ... More
Investigating the roots of the nonlinear Luttinger liquid phenomenologyApr 12 2019The nonlinear Luttinger liquid phenomenology of one-dimensional correlated Fermi systems is an attempt to describe the effect of the band curvature beyond the Tomonaga-Luttinger liquid paradigm. It relies on the observation that the dynamical structure ... More
Tunneling conductance of a mesoscopic ring with spin-orbit coupling and Tomonaga-Luttinger interactionMar 08 2006Sep 08 2006We study the tunneling current through a mesoscopic two-terminal ring with spin-orbit coupling, which is threaded by a magnetic flux. The electron-electron interaction in the ring is described in terms of a Tomonaga-Luttinger model which also allows us ... More
Investigating the roots of the nonlinear Luttinger liquid phenomenologyApr 12 2019Jun 06 2019The nonlinear Luttinger liquid phenomenology of one-dimensional correlated Fermi systems is an attempt to describe the effect of the band curvature beyond the Tomonaga-Luttinger liquid paradigm. It relies on the observation that the dynamical structure ... More
Nonequilibrium functional RG with frequency dependent vertex function: A study of the single impurity Anderson modelNov 30 2009May 27 2010We investigate nonequilibrium properties of the single impurity Anderson model by means of the functional renormalization group (fRG) within Keldysh formalism. We present how the level broadening Gamma/2 can be used as flow parameter for the fRG. This ... More
Properties of multi-particle Green and vertex functions within Keldysh formalismFeb 13 2009Mar 03 2010The increasing interest in nonequilibrium effects in condensed matter theory motivates the adaption of diverse equilibrium techniques to Keldysh formalism. For methods based on multi-particle Green or vertex functions this involves a detailed knowledge ... More
Semiclassical theory of spin-orbit interactions using spin coherent statesMar 09 2002Jul 23 2002We formulate a semiclassical theory for systems with spin-orbit interactions. Using spin coherent states, we start from the path integral in an extended phase space, formulate the classical dynamics of the coupled orbital and spin degrees of freedom, ... More
A renormalization-group analysis of the interacting resonant level model at finite bias: Generic analytic study of static properties and quench dynamicsOct 27 2010Nov 22 2012Using a real-time renormalization group method we study the minimal model of a quantum dot dominated by charge fluctuations, the two-lead interacting resonant level model, at finite bias voltage. We develop a set of RG equations to treat the case of weak ... More
Competing effects of interactions and spin-orbit coupling in a quantum wireSep 25 2004Mar 07 2005We study the interplay of electron-electron interactions and Rashba spin-orbit coupling in one-dimensional ballistic wires. Using the renormalization group approach we construct the phase diagram in terms of Rashba coupling, Tomonaga-Luttinger stiffness ... More
Periodic orbit theory including spin degrees of freedomSep 02 2003We summarize recent developments of the semiclassical description of shell effects in finite fermion systems with explicit inclusion of spin degrees of freedom, in particluar in the presence of spin-orbit interactions. We present a new approach that makes ... More
Functional renormalization group study of the interacting resonant level model in and out of equilibriumNov 26 2009Mar 01 2010We investigate equilibrium and steady-state non-equilibrium transport properties of a spinless resonant level locally coupled to two conduction bands of width ~\Gamma via a Coulomb interaction U and a hybridization t'. In order to study the effects of ... More
Magnetic field effects on the finite-frequency noise and ac conductance of a Kondo quantum dot out of equilibriumNov 29 2012Jun 18 2013We present analytic results for the finite-frequency current noise and the nonequilibrium ac conductance for a Kondo quantum dot in presence of a magnetic field. Using the real-time renormalization group method, we determine the line shape close to resonances ... More
On the extra phase correction to the semiclassical spin coherent-state propagatorApr 04 2003Jan 12 2004The problem of an origin of the Solary-Kochetov extra-phase contribution to the naive semiclassical form of a generalized phase-space propagator is addressed with the special reference to the su(2) spin case which is the most important in applications. ... More
Control over few photon pulses by a time-periodic modulation of the photon-emitter couplingApr 04 2017We develop a Floquet scattering formalism for the description of quasistationary states of microwave photons in a one-dimensional waveguide interacting with a nonlinear cavity by means of a periodically modulated coupling. This model is inspired by the ... More
Oscillatory dynamics and non-markovian memory in dissipative quantum systemsNov 01 2012Mar 13 2013The nonequilibrium dynamics of a small quantum system coupled to a dissipative environment is studied. We show that (1) the oscillatory dynamics close to a coherent-to-incoherent transition is surprisingly different from the one of the classical damped ... More
Comparative study of theoretical methods for nonequilibrium quantum transportJan 21 2010May 01 2010We present a detailed comparison of three different methods designed to tackle nonequilibrium quantum transport, namely the functional renormalization group (fRG), the time-dependent density matrix renormalization group (tDMRG), and the iterative summation ... More
Non-equilibrium current and relaxation dynamics of a charge-fluctuating quantum dotNov 29 2009Jul 07 2010We study the steady-state current in a minimal model for a quantum dot dominated by charge fluctuations and analytically describe the time evolution into this state. The current is driven by a finite bias voltage V across the dot, and two different renormalization ... More
The quench dynamics of a dissipative quantum system: a renormalization group studyJul 11 2013Oct 22 2013We study dissipation in a small quantum system coupled to an environment held in thermodynamic equilibrium. The relaxation dynamics of a system subject to an abrupt quench in the parameters of the underlying Hamiltonian is investigated using two complementary ... More
Quantum theory of light scattering in a one-dimensional channel: Interaction effect on photon statistics and entanglement entropyApr 13 2015Jun 23 2015We provide a complete and exact quantum description of coherent light scattering in a one-dimensional multi-mode transmission line coupled to a two-level emitter. Using recently developed scattering approach we discuss transmission properties, power spectrum, ... More
Scattering of massless particles in one-dimensional chiral channelMar 02 2012Jul 02 2012We present a general formalism describing a propagation of an arbitrary multiparticle wave packet in a one-dimensional multimode chiral channel coupled to an ensemble of emitters which are distributed at arbitrary positions. The formalism is based on ... More
Scattering of two photons from two distant qubits: Exact solutionJun 06 2014Nov 08 2014We consider the inelastic scattering of two photons from two qubits separated by an arbitrary distance $R$ and coupled to a one-dimensional transmission line. We present an exact, analytical solution to the problem, and use it to explore a particular ... More
Spin-density induced by electromagnetic wave in two-dimensional electron gas with both Rashba and Dresselhaus spin-orbit couplingsAug 19 2008Aug 19 2008We consider the magnetic response of a two-dimensional electron gas (2DEG) with both Rashba and Dresselhaus spin-orbit coupling to a microwave excitation. We generalize the results of [A. Shnirman and I. Martin, Europhys. Lett. 78, 27001 (2007).], where ... More
Nonequilibrium Kondo model: Crossover from weak to strong couplingJan 30 2012Jul 10 2012We analyze the nonequilibrium Kondo model at finite voltage and temperature by using a new formulation of the real-time renormalization group method with the Laplace variable as the flow parameter. We evaluate the energy-dependent spin relaxation rate ... More
Semiclassical theory of spin-orbit interaction in the extended phase spaceFeb 06 2003May 05 2003We consider the semiclassical theory in a joint phase space of spin and orbital degrees of freedom. The method is developed from the path integrals using the spin-coherent-state representation, and yields the trace formula for the density of states. We ... More
Non-equilibrium transport through quantum dots with Dzyaloshinsky--Moriya--Kondo interactionApr 27 2011Jul 29 2011We study non-equilibrium transport through a single-orbital Anderson model in a magnetic field with spin-dependent hopping amplitudes. In the cotunneling regime it is described by an effective spin-1/2 dot with a Dzyaloshinsky--Moriya--Kondo (DMK) interaction ... More
Scaling of the Kondo zero bias peak in a hole quantum dot at finite temperaturesMay 07 2013We have measured the zero bias peak in differential conductance in a hole quantum dot. We have scaled the experimental data with applied bias and compared to real time renormalization group calculations of the differential conductance as a function of ... More
Few-mode geometric description of driven-dissipative phase transition in an open quantum systemJul 31 2018Mar 28 2019By example of the nonlinear Kerr-mode driven by a laser, we show that hysteresis phenomena in systems featuring a driven-dissipative phase transition (DPT) can be accurately described in terms of just two collective, dissipative Liouvillian eigenmodes. ... More
Topologically protected strongly-correlated states of photonsDec 27 2012Dec 16 2014Hybrid photonic nanostructures allow the engineering of novel interesting states of light. One recent example is topological photonic crystals where a nontrivial Berry phase of the photonic band structure gives rise to topologically protected unidirectionally-propagating ... More
Full counting statistics of photons interacting with emitterFeb 08 2013A complete characterization of quantum fluctuations in many-body systems is accessible through the full counting statistics. We present an exact computation of statistical properties of light in a basic model of light-matter interaction: a multimode photonic ... More
Few photon scattering on Bose-Hubbard latticesMay 30 2017Aug 01 2017We theoretically investigate the scattering of few photon light on Bose-Hubbard lattices using diagrammatic scattering theory. We explicitly derive general analytical expressions for the lowest order photonic correlation functions, which we apply numerically ... More
Photonic Kondo modelNov 29 2016Here we introduce and study a photonic analogue of the Kondo model. The model is defined as a far detuned regime of photonic scattering off a three-level emitter in a $\Lambda$-type configuration coupled to a one-dimensional transmission line with linear ... More
Supersymmetry in quantum optics and in spin-orbit coupled systemsJul 19 2014Light-matter interaction is naturally described by coupled bosonic and fermionic subsystems. This suggests that a certain Bose-Fermi duality is naturally present in the fundamental quantum mechanical description of photons interacting with atoms. We reveal ... More
Kondo model in nonequilibrium: Interplay between voltage, temperature, and crossover from weak to strong couplingMay 13 2014Sep 18 2014We consider an open quantum system in contact with fermionic metallic reservoirs in a nonequilibrium setup. For the case of spin, orbital or potential fluctuations, we present a systematic formulation of real-time renormalization group at finite temperature, ... More
Relaxation vs decoherence: Spin and current dynamics in the anisotropic Kondo model at finite bias and magnetic fieldOct 01 2009Mar 09 2010Using a nonequilibrium renormalization group method we study the real-time evolution of spin and current in the anisotropic Kondo model (both antiferromagnetic and ferromagnetic) at finite magnetic field $h_0$ and bias voltage $V$. We derive analytic ... More
Delayed Coherent Quantum Feedback from a Scattering Theory and a Matrix Product State PerspectiveJun 23 2017Sep 14 2017We study the scattering of photons propagating in a semi-infinite waveguide terminated by a mirror and interacting with a quantum emitter. This paradigm constitutes an example of coherent quantum feedback, where light emitted towards the mirror gets redirected ... More
Five approaches to exact open-system dynamics: Complete positivity, divisibility and time-dependent observablesMar 11 2019To extend the classical concept of Markovianity to an open quantum system, different notions of the divisibility of its dynamics have been introduced. Here we analyze this issue by five complementary approaches: equations of motion, real-time diagrammatics, ... More
A tunable, nonlinear Hong-Ou-Mandel interferometerDec 23 2014We investigate the two-photon scattering properties of a Jaynes-Cummings (JC) nonlinearity consisting of a two-level system (qubit) interacting with a single mode cavity, which is coupled to two waveguides, each containing a single incident photon wave ... More
Quantum choppersMar 17 2016An optical chopper periodically interrupts a classical light beam. We propose a realizable quantum version of the optical chopper, where the time-periodic driving of the light-matter coupling is achieved through a nonlinear three wave mixing element. ... More
Exceptional and regular spectra of a generalized Rabi modelJul 30 2013Dec 05 2014We study the spectrum of the generalized Rabi model in which co- and counter-rotating terms have different coupling strengths. It is also equivalent to the model of a two-dimensional electron gas in a magnetic field with Rashba and Dresselhaus spin-orbit ... More
Non-adiabatic effects in periodically driven-dissipative open quantum systemsFeb 23 2018We present a general method to calculate the quasi-stationary state of a driven-dissipative system coupled to a transmission line (and more generally, to a reservoir) under periodic modulation of its parameters. Using Floquet's theorem, we formulate the ... More
The giant acoustic atom --- a single quantum system with a deterministic time delayDec 02 2016We investigate the quantum dynamics of a single transmon qubit coupled to surface acoustic waves (SAWs) via two distant connection points. Since the acoustic speed is five orders of magnitude slower than the speed of light, the travelling time between ... More
The giant acoustic atom --- a single quantum system with a deterministic time delayDec 02 2016Apr 19 2017We investigate the quantum dynamics of a single transmon qubit coupled to surface acoustic waves (SAWs) via two distant connection points. Since the acoustic speed is five orders of magnitude slower than the speed of light, the travelling time between ... More
A new signal for scalar top bound state productionOct 01 1993We study the production and decay of a scalar \stst\ bound state \sigst\ at hadron supercolliders, where \st\ is the lighter stop eigenstate. If \st\ has no tree--level 2--body decays, the dominant decay modes of \sigst\ are $gg$ or, if $m_h < \mst \ll ... More
Neutralino-Nucleon Scattering RevisitedJul 01 1993We present a detailed discussion of the elastic scattering of a supersymmetric neutralino off a nucleon or nucleus, with emphasis on the spin--independent interaction. We carefully treat QCD effects on the squark exchange contribution. In particular, ... More
Quantum information processing: The case of vanishing interaction energyOct 27 2002We investigate the rate of operation of quantum "black boxes" ("oracles") and point out the possibility of performing an operation by a quantum "oracle" whose average energy equals zero. This counterintuitive result not only presents a generalization ... More
Self-Organized Topological State with Majorana FermionsJul 08 2013Nov 06 2013Topological phases, quite generally, are difficult to come by. They either occur under rather extreme conditions (e.g. the quantum Hall liquids, which require high sample purity, strong magnetic fields and low temperatures) or demand fine tuning of system ... More
Spin Response of Electrons on the Surface of a Topological InsulatorJan 11 2012The surface of a topological insulator hosts a very special form of a quasi-two dimensional metallic system when it is embedded in a topologically trivial medium like the vacuum. The electronic properties of this unusual 2D metal are distinct in many ... More
Lorentz Conserving Noncommutative Standard ModelMar 29 2007May 10 2007We consider Lorentz conserving noncommutative field theory to construct the Lorentz conserving noncommutative standard model based on the gauge group $SU(3)\times SU(2)\times U(1)$. We obtain the enveloping algebra-valued of Higgs field up to the second ... More
Shelving and Probe Efficiency in Trapped Ion ExperimentsFeb 24 2014A generalized probe sequence typical of trapped ion experiments using shelving is studied. Detection efficiency is analyzed for finite shelved state lifetimes and using multi-modal count distributions. Multi-modal distributions are more appropriate for ... More
The Neutralino Relic Density in Minimal N=1 SupergravityJul 10 1992We compute the cosmic relic (dark matter) density of the lightest supersymmetric particle (LSP) in the framework of minimal $N=1$ Supergravity models with radiative breaking of the electroweak gauge symmetry. To this end, we re--calculate the cross sections ... More
Quantization and $2π$ Periodicity of the Axion Action in Topological InsulatorsJun 17 2010Nov 10 2010The Lagrangian describing the bulk electromagnetic response of a three-dimensional strong topological insulator contains a topological `axion' term of the form '\theta E dot B'. It is often stated (without proof) that the corresponding action is quantized ... More
Massive Neutrino in Non-commutative Space-timeDec 24 2007Apr 01 2008We consider the noncommutative standard model based on $SU(3)\times SU(2)\times U(1)$. We study the gauge transformation of right handed neutrino and its direct interaction with photon in the noncommutative space-time. We show that the massive Dirac neutrinos, ... More
Infinite order excitonic Bloch equations for asymmetric nanostructuresJul 04 2003We present a new exciton-based formalism for calculating the coherent response of asymmetric semiconductor multiple quantum well structures to ultra-short optical pulses valid to infinite order in the optical field and including the self-generated intraband ... More
Scalar StoponiumAug 18 1993We study the decays of a scalar \stst\ bound state \sigst, where \st\ is the lighter stop eigenstate. If \st\ has no tree--level 2--body decays, the dominant decay modes of \sigst\ are $gg$ or, if $m_h < \mst \ll \mstt$, a pair of light scalar Higgs bosons ... More
Production and Decay of Scalar Stoponium Bound StatesDec 02 1993In this paper we discuss possible signatures for the production of scalar \stst\ (stoponium) bound states \sigst\ at hadron colliders, where \st\ is the lighter scalar top eigenstate. We first study the decay of \sigst; explicit expressions are given ... More
Parton Model in Lorentz Invariant Non-Commutative SpaceMay 26 2004Aug 22 2004We consider the Lorentz invariant non-commutative QED and complete the Feynman rules for the theory up to the order $\theta^2$. In the Lorentz invariant version of the non-commutative QED the particles with fractional charges can be also considered. We ... More
Electromagnetic Response of Weyl SemimetalsMar 22 2013Jun 27 2013It has been suggested recently, based on subtle field-theoretical considerations, that the electromagnetic response of Weyl semimetals and the closely related Weyl insulators can be characterized by an axion term E.B with space and time dependent axion ... More
The Charm Quark Contribution to the Proton Structure FunctionOct 14 2006Dec 27 2006The charm quark structure function $F^c_2$ and the longitudinal structure function $F_l^p$ are directly sensitive to the gluon content of proton and therefore are crucial in understanding of proton structure function, in particular at low momentum transfer ... More
The decay of singlet scalar dark matter to unparticle and photonMay 06 2008We consider the unparticle physics introduced by Georgi and show that if the standard model is extended to include a singlet scalar as a dark matter candidate, there is a channel which leads to its decay to photon and unparticle. We calculate the decay ... More
Photon Neutrino Scattering in Non-Commutative SpaceNov 04 2005Jan 19 2006We extend the non-commutative standard model based on the minimal $SU(3)\times SU(2)\times U(1)$ gauge group to include the interaction of photon with neutrino. We show that, in the gauge invariant manner, only the right handed neutrino can directly couple ... More
On the effect of the thermal gas component to the stability of vortices in trapped Bose-Einstein condensatesMar 12 2002We study the stability of vortices in trapped single-component Bose-Einstein condensates within self-consistent mean-field theories--especially we consider the Hartree-Fock-Bogoliubov-Popov theory and its recently proposed gapless extensions. It is shown ... More
Phase boundaries of a spin-3/2 Blume-Emery-Griffiths model on a honeycomb latticeOct 11 2013The spin-3/2 Blume-Emery-Griffiths model on a honeycomb lattice is studied by Monte Carlo simulations with the goal to determine phase diagrams for a range of the model parameters and to investigate the nature of the phase transitions between the respective ... More
Flares on A-type stars: Evidence for heating of solar corona by nanoflares?Aug 11 2016We analyzed the occurrence rates of flares on stars of spectral types K, G, F, and A, observed by Kepler. We found that the histogram of occurrence frequencies of stellar flares is systematically shifted towards a high-energy tail for A-type stars compared ... More
The Formation Rates of Population III Stars and Chemical Enrichment of Halos during the Reionization EraJan 06 2009[abridged] The First Stars in the Universe form out of pristine primordial gas clouds that have been radiatively cooled to a few hundreds of degrees Kelvin either via molecular or atomic (Lyman-Alpha) hydrogen lines. This primordial mode of star formation ... More
Symmetry Adaptation Techniques in n-Photon Absorption SpectroscopyOct 27 1998We present some recent progress achieved in the application of symmetry adaptation techniques to n-photon absorption spectroscopy of rare earth ions in finite symmetry. More specifically, this work is concerned with the determination of the intensity ... More
Two-Photon Spectroscopy of Transition-Metal Ions in Cubical SymmetryOct 26 1998Symmetry adaptation techniques are applied to the determination of intensities of intra-configurational two-photon transitions for transition-metal ions in cubical symmetry. This leads to a simple model giving the polarization dependence of intensities ... More
An Alternative Basis for the Wigner-Racah Algebra of the Group SU(2)Dec 17 1997The Lie algebra of the classical group SU(2) is constructed from two quon algebras for which the deformation parameter is a common root of unity. This construction leads to (i) a not very well-known polar decomposition of the ladder generators of the ... More
Enhanced Sampling in the Well-Tempered EnsembleOct 26 2009Apr 13 2010We introduce the well-tempered ensemble (WTE) which is the biased ensemble sampled by well-tempered metadynamics when the energy is used as collective variable. WTE can be designed so as to have approximately the same average energy as the canonical ensemble ... More
Berry's Phase Induced Bose-Einstein condensation into a Vortex StateNov 23 1998The existence of a geometric phase in magnetic traps can be used to Bose condense a magnetically trapped atomic gas into a vortex state. We propose an experimental setup where a magnetic trap together with a blue detuned laser beam form a multiply connected ... More
Superconducting state in Fe-based materials and spin-fluctuation theory of pairingOct 28 2015Short review of the spin-fluctuation theory of superconductive pairing in iron-based pnictides and chalcogenides.
QCD_{1+1} with Static Quarks as Supersymmetric Quantum MechanicsFeb 09 1998We reexamine the solvable model problem of two static, fundamental quarks interacting with a SU(2) Yang-Mills field on a spatial circle, introduced by Engelhardt and Schreiber. If the quarks are at the same point, the model exhibits a quantum mechanical ... More
Massive Binary Black Holes in the Cosmic LandscapeJun 23 2009Binary black holes occupy a special place in our quest for understanding the evolution of galaxies along cosmic history. If massive black holes grow at the center of (pre-)galactic structures that experience a sequence of merger episodes, then dual black ... More
Effect of inelastic scattering on parametric pumpingAug 03 2001Pumping of charge in phase-coherent mesoscopic systems due to the out-of-phase modulation of two parameters has recently found considerable interest. We investigate the effect of inelastic processes on the adiabatically pumped current through a two terminal ... More
Hidden quantum pump effects in quantum coherent ringsFeb 27 2003Time periodic perturbations of an electron system on a ring are examined. For small frequencies periodic small amplitude perturbations give rise to side band currents which in leading order are inversely proportional to the frequency. These side band ... More
Dynamic scattering channels of a double barrier structureApr 02 2008We calculate analytically the Floquet scattering matrix for a periodically driven double-barrier structure. Our approach takes into account dynamical effects which become necessarily important when electrons propagate through a system subject to a fast ... More
Dissipation and noise in adiabatic quantum pumpsJan 16 2002We investigate the distribution function, the heat flow and the noise properties of an adiabatic quantum pump for an arbitrary relation of pump frequency $\omega$ and temperature. To achieve this we start with the scattering matrix approach for ac-transport. ... More
Remarks on the high-energy behaviour of cross-sections in weak-scale string theoriesSep 20 2001We consider the high-energy behaviour of processes involving Kaluza-Klein (KK) gravitons of weak-scale string theories. We discuss how form-factors derived within string theory modify the couplings of KK gravitons and thereby lead to an exponential fall-off ... More
Metastability in Two Dimensions and the Effective PotentialApr 12 1993We study analytically and numerically the decay of a metastable phase in (2+1)-dimensional classical scalar field theory coupled to a heat bath, which is equivalent to two-dimensional Euclidean quantum field theory at zero temperature. By a numerical ... More
New analyticity constraints on the high energy behavior of hadron-hadron cross sectionsJan 25 2006Mar 16 2006We here comment on a series of recent papers by Igi and Ishida[K. Igi and M. Ishida, Phys. Lett B 622, 286 (2005)] and Block and Halzen[M. M. Block and F. Halzen, Phys. Rev D 72, 036006 (2005)] that fit high energy $pp$ and $\bar pp$ cross section and ... More
Factorization Theorems for High Energy nn, gamma p and gamma gamma ScatteringFeb 17 2003The robustness of the factorization theorem for total cross sections, $\sigma_{nn}/\sigma_{\gamma p}=\sigma_{\gamma p}/\sigma_{\gamma\gamma}$, originally proved by Block and Kaidalov\cite{bk} for $nn$ (the even portion of $pp$ and $\pbar p$ scattering), ... More
Visualising a FuseOct 27 2010Nov 09 2010In this brief article I describe an experiment to illustrate how a fuse works. I have used this as part of lessons for my year 11 classes to demonstrate how an electrical fuse 'blows' when too high a current passes through it.
General models of Einstein gravity with a non-Newtonian weak-field limitJan 08 2009We investigate Einstein theories of gravity, coupled to a scalar field \vphi and point-like matter, which are characterized by a scalar field-dependent matter coupling function e^{H(\vphi)}. We show that under mild constraints on the form of the potential ... More
Two Loop Electroweak Bosonic Corrections to the Muon Decay LifetimeNov 04 2002Nov 19 2002A review of the calculation of the two loop bosonic corrections to $\Delta r$ is presented. Factorization and matching onto the Fermi model are discussed. An approximate formula, describing the quantity over the interesting range of Higgs boson mass values ... More
Structure and stability of Al$_2$FeJul 01 2011We employ first principles total energy and phonon calculations to address the structure and stability of Al$_2$Fe. This structure, which is reported as stable in the assessed Al-Fe phase diagram, is distinguished by an unusually low triclinic symmetry. ... More
Stability of Fe-based alloys with structure type C6Cr23Jul 23 2004Bulk metallic glass forms when liquid metal alloys solidify without crystalization. In the search for Iron-based bulk glass-forming alloys of the metal-metalloid type (Fe-B- and Fe-C-based), crystals based on the structural prototype C6Cr23 often preempt ... More
Cohesive energies of Fe-based glass-forming alloysMay 13 2004We calculate the cohesive energies of Fe-based glass-forming alloys in the B-Fe-Y-Zr quaternary system. Our {\it ab-initio} calculations fully relax atomic positions and lattice parameters yielding enthalpies of mixing at T=0K. We examine both the known ... More
Efficiently Extracting Energy from Cosmological NeutrinosJul 02 2013Aug 20 2013Detecting the extremely low-energy neutrinos that form the Cosmic Neutrino Background (CNB) presents many experimental challenges, but pursuing this elusive goal is still worthwhile because these weakly-interacting particles could provide a new window ... More
Are the sungrazing comets the inner source of pickup ions and energetic neutral atoms?May 07 2004Feb 11 2005We present arguments that at least part of the inner source of pickup ions in the solar wind might be the material released by sungrazing comets. Based on a statistical analysis of sungrazing comets detected over almost eight years of LASCO operation ... More
Beyond the Kolmogorov Johnson Mehl Avrami kinetics: inclusion of the spatial correlationApr 16 2003The Kolmogorov-Johnson-Mehl-Avrami model, which is a nucleation and growth poissonian process in space, has been implemented by taking into account spatial correlation among nuclei. This is achieved through a detailed study of a system of distinguishable ... More
On the stability operator for MOTS and the 'core' of Black HolesOct 13 2012Small deformations of marginally (outer) trapped surfaces are considered by using their stability operator. In the case of spherical symmetry, one can use these deformations on any marginally trapped round sphere to prove several interesting results. ... More
On the boundary of the region containing trapped surfacesDec 15 2008The boundary of the region in spacetime containing future-trapped closed surfaces is considered. In asymptotically flat spacetimes, this boundary does not need to be the event horizon nor a dynamical/trapping horizon. Some properties of this boundary ... More