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2007-02-12
Output radiation from a degenerate parametric oscillator
We study the squeezing as well as the statistical properties of the output radiation from a degenerate parametric oscillator coupled to a squeezed vacuum reservoir employing the stochastic differential equations associated with the normal ordering. It is found that the degree of squeezing of the output radiation is les...
0702108v1
2007-03-20
Decoherence of an $n$-qubit quantum memory
We analyze decoherence of a quantum register in the absence of non-local operations i.e. of $n$ non-interacting qubits coupled to an environment. The problem is solved in terms of a sum rule which implies linear scaling in the number of qubits. Each term involves a single qubit and its entanglement with the remaining o...
0703190v1
1995-07-24
Henon-Heiles Hamiltonian for Coupled Upper-Hybrid and Magnetoacoutic Waves in Magnetized Plasmas
We show that the coupled mode equations for the stationary propagation of upper--hybrid and magnetoacoustic waves in magnetized electron--ion plasmas with negative group dispersion can be exactly derived from the generalized \Henon--Heiles Hamiltonian. The parameter regimes for the integrable cases of the coupled mode ...
9507005v1
1998-04-09
The Davey Stewartson system and the Bäcklund Transformations
We consider the (coupled) Davey-Stewartson (DS) system and its B\"{a}cklund transformations (BT). Relations among the DS system, the double Kadomtsev-Petviashvili (KP) system and the Ablowitz-Ladik hierarchy (ALH) are established. The DS hierarchy and the double KP system are equivalent. The ALH is the BT of the DS sys...
9804009v2
1999-05-10
Coupled nonlinear Schrodinger equations with cubic-quintic nonlinearity: Integrability and soliton interaction in non-Kerr media
We propose an integrable system of coupled nonlinear Schrodinger equations with cubic-quintic terms describing the effects of quintic nonlinearity on the ultra-short optical soliton pulse propagation in non-Kerr media. Lax pair, conserved quantities and exact soliton solutions for the proposed integrable model are give...
9905006v1
1999-08-09
A Coupled AKNS-Kaup-Newell Soliton Hierarchy
A coupled AKNS-Kaup-Newell hierarchy of systems of soliton equations is proposed in terms of hereditary symmetry operators resulted from Hamiltonian pairs. Zero curvature representations and tri-Hamiltonian structures are established for all coupled AKNS-Kaup-Newell systems in the hierarchy. Therefore all systems have ...
9908005v1
1995-11-21
Synchronization in one-dimensional array of Josephson coupled thin layers
We obtain self-consistent macroscopic equations describing interlayer Josephson effect and intralayer disequilibrium in one-dimensional array of Josephson coupled layers. We show that ``nonequilibrium coupling'' can lead to effective spatial and time synchronization and formation of coherent dynamic resistive state (co...
9511001v1
1996-05-11
Coupling of Josephson flux-flow oscillators to an external RC load
We investigate by numerical simulations the behavior of the power dissipated in a resistive load capacitively coupled to a Josephson flux flow oscillator and compare the results to those obtained for a d.c. coupled purely resistive load. Assuming realistic values for the parameters R and C, both in the high- and in the...
9605002v1
2007-04-05
Circuit QED with a Flux Qubit Strongly Coupled to a Coplanar Transmission Line Resonator
We propose a scheme for circuit quantum electrodynamics with a superconducting flux-qubit coupled to a high-Q coplanar resonator. Assuming realistic circuit parameters we predict that it is possible to reach the strong coupling regime. Routes to metrological applications, such as single photon generation and quantum no...
0704.0727v3
2007-04-06
Coupling of whispering-gallery modes in size-mismatched microdisk photonic molecules
Mechanisms of whispering-gallery (WG) modes coupling in microdisk photonic molecules (PMs) with slight and significant size mismatch are numerically investigated. The results reveal two different scenarios of modes interaction depending on the degree of this mismatch and offer new insight into how PM parameters can be ...
0704.0820v1
2007-04-06
Gauge-Higgs Unification and LHC/ILC
In the gauge-Higgs unification scenario the 4D Higgs field is identified with the zero mode of the extra-dimensional component of gauge potentials. The mass of the Higgs particle in the unification in the Randall-Sundrum warped spacetime is predicted to be in the range 100 GeV - 300 GeV. The WWZ gauge couplings remains...
0704.0883v1
2007-04-17
Theoretical treatments of fusion processes in collisions of weakly bound nuclei
We review the theoretical methods to evaluate fusion cross sections in collisions of weakly bound nuclei. We piont out that in such collisions the coupling to the breakup channel leads to the appearance of different fusion processes. The extentsion of the coupled-channel method to coupling with the continuum is the mos...
0704.2176v1
2007-04-22
On some Hamiltonian structures of coupled Painlevé II systems in dimension four
We find and study a two-parameter family of coupled Painlev\'e II systems in dimension four with affine Weyl group symmetry of several types. Moreover, we find a three-parameter family of polynomial Hamiltonian systems in two variables $t,s$. Setting $s=0$, we can obtain an autonomous version of the coupled Painlev\'e ...
0704.2863v2
2007-04-27
Notes on Superconformal Chern-Simons-Matter Theories
The three dimensional N=2 supersymmetric Chern-Simons theory coupled to matter fields, possibly deformed by a superpotential, give rise to a large class of exactly conformal theories with Lagrangian descriptions. These theories can be arbitrarily weakly coupled, and hence can be studied perturbatively. We study the the...
0704.3740v1
2007-04-30
Effective tuning of exciton polarization splitting in coupled quantum dots
The polarization splitting of the exciton ground state in two laterally coupled quantum dots under an in-plane electric field is investigated and its effective tuning is designed. It is found that there are significant Stark effect and anticrossing in energy levels. Due to coupling between inter- and intra-dot states, ...
0704.3871v2
2007-05-03
Coupled spin-charge drift-diffusion equations for the Rashba model
Coupled spin-charge drift-diffusion equations are derived for a biased two-dimensional electron gas with weak Rashba spin-orbit interaction. The basic equations formally agree with recent results obtained for spin-orbit coupled small polarons. It is shown that effects of an in-plane electric field on a homogeneous spin...
0705.0415v1
2007-05-03
On the blow-up threshold for weakly coupled nonlinear Schroedinger equations
We study the Cauchy problem for a system of two coupled nonlinear focusing Schroedinger equations arising in nonlinear optics. We discuss when the solutions are global in time or blow-up in finite time. Some results, in dependence of the data of the problem, are proved; in particular we give a bound, depending on the c...
0705.0491v1
2007-05-06
On the gravitational coupling of Hadamard states
We study the constraints imposed by the Hadamard condition on the two-point function of local states of a scalar quantum field conformally coupled to a gravitational background. We propose a method to assign a stress tensor to the state-dependent part of the two point function which arises as a conserved tensor with an...
0705.0787v1
2007-05-07
Characteristics of Switchable Superconducting Flux Transformer with DC Superconducting Quantum Interference Device
We have investigated the flux transfer characteristics of a switchable flux transformer comprising a superconducting loop and a DC superconducting quantum interference device (DC-SQUID). This system can be used to couple multiple flux qubits with a controllable coupling strength. Its characteristics were measured using...
0705.0841v1
2007-05-09
Nonradiative DKR processes: revisiting the theory. II. Electron-vibrational mode coupling
We summarize a few proposals for mixing F center states through the mediation of an appropriate symmetry-breaking vibrational mode. Electron-mode coupling energies odd-order in the mode coordinates are characteristic of the pseudo-Jahn-Teller mixing of nearly-degenerate opposite-parity electronic states mediated by an ...
0705.1361v1
2007-05-17
The effective potential and resummation procedure to multidimensional complex cubic potentials for weak and strong-coupling
The method for the recursive calculation of the effective potential is applied successfully in case of weak coupling limit (g tend to zero) to a multidimensional complex cubic potential. In strong-coupling limit (g tend to infinity), the result is resumed using the variational perturbation theory (VPT). It is found tha...
0705.2571v1
2007-05-19
Three-dimensional instability of two nonlinearly coupled electromagnetic waves in a plasma
The three-dimensional instability of two coupled electromagnetic waves in an unmagnetized plasma is investigated theoretically and numerically. In the regime of two-plasmon decay, where one pump wave frequency is approximately twice the electron plasma frequency, we find that the coupled pump waves give rise to enhance...
0705.2839v1
2007-05-24
Thermal entanglement in a two-qutrit system with nonlinear coupling under nonuniform external magnetic field
We study the thermal entanglement of a 2-qutrit spin chain with nonlinear coupling in the presence of nonuniform magnetic field. Thermal entanglement of an arbitrary (finite dimensional) m-partite system vanishes at some finite threshold temperature T_s. We investigate the dependence of T_s on the system's parameters, ...
0705.3568v2
2007-05-28
Circumventing Astrophysical Bounds Upon PVLAS Experiment
We study the possibility of evading astrophysical bound on light pseudoscalars. We argue that the solar bounds can be evaded if we have a sufficiently strong self-coupling of the pseudoscalars. The required coupling does not conflict with any known experimental bounds. We also show that it is possible to find a couplin...
0705.3967v2
2007-06-05
Spin-charge-lattice coupling near the metal-insulator transition in Ca3Ru2O7
We report x-ray scattering studies of the c-axis lattice parameter in Ca3Ru2O7 as a function of temperature and magnetic field. These structural studies complement published transport and magnetization data, and therefore elucidate the spin-charge-lattice coupling near the metal-insulator transition. Strong anisotropy ...
0706.0689v1
2007-06-10
Antiferromagnetism and Superconductivity in a model of Quasi 1D Organic Conductors
I apply a two-step renormalization group method to the study of the competition between antiferromagnetism (AFM) and superconductivity in an anisotropic 2D Hubbard model. I show that this simple model captures the essentials of the ground-state phases of the quasi 1D organic conductors. As found experimentally, the gro...
0706.1364v1
2007-06-11
Universality of traveling waves with QCD running coupling
``Geometric scaling'', i.e. the dependence of DIS cross-sections on the ratio Q/Q_S, where Q_S(Y) is the rapidity-dependent \saturation scale, can be theoretically obtained from universal ``traveling wave'' solutions of the nonlinear Balitsky-Kovchegov (BK) QCD evolution equation at fixed coupling. We examine the simil...
0706.1457v2
2007-06-13
Failure of standard approximations of the exchange coupling in nanostructures
We calculate the exchange coupling for a double dot system using a novel, numerically exact yet efficient technique, based on finite-element methods. Specifically, we evaluate the exchange coupling both for a quasi-one and a two-dimensional system, also including an applied magnetic field. Our numerical results provide...
0706.1859v2
2007-06-14
Infrared Limit of Gluon Amplitudes at Strong Coupling
In this note, we propose that the infrared structure of gluon amplitudes at strong coupling can be fully extracted from a local consideration near cusps. This is consistent with field theory and correctly reproduces the infrared divergences of the four-gluon amplitude at strong coupling calculated recently by Alday and...
0706.2015v3
2007-06-15
Phase rigidity breaking in open Aharonov-Bohm ring coupled to a cantilever
The conductance and the transmittance phase shifts of a two-terminal Aharonov-Bohm (AB) ring are analyzed in the presence of mechanical displacements due to coupling to an external can- tilever. We show that phase rigidity is broken, even in the linear response regime, by means of inelastic scattering due to phonons. O...
0706.2263v1
2007-06-26
The coupling constants for an electroweak model with a $SU(4)_{PS} \otimes SU(4)_{EW}$ unification symmetry
We introduce the sequence of spontaneous symmetry breaking of a coupling between Pati-Salam and electroweak symmetries $SU(4)_{PS} \otimes SU(4)_{EW}$ in order to establish a mathematically consistent relation among the coupling constants at grand unification energy scale. With the values of baryon minus lepton quantum...
0706.3931v1
2007-07-01
Sakai-Sugimoto Brane System at High Density
The D4-D8 brane system of Sakai-Sugimoto model at high quark density is studied in the weak coupling regime. We show that the color superconducting phase (for Nc~3) or the chiral density wave (for Nc->infinity) disappears at very large chemical potential, or equivalently at very large compactified dimension that the mo...
0707.0101v3
2007-07-02
Three-port beam splitters-combiners for interferometer applications
We derive generic phase and amplitude coupling relations for beam splitters-combiners that couple a single port with three output ports or input ports, respectively. We apply the coupling relations to a reflection grating that serves as a coupler to a single-ended Fabry-Perot ring cavity. In the impedance-matched case ...
0707.0206v1
2007-07-03
Vibrating Superconducting Island in a Josephson Junction
We consider a combined nanomechanical-supercondcuting device that allows the Cooper pair tunneling to interfere with the mechanical motion of the middle superconducting island. Coupling of mechanical oscillations of a superconducting island between two superconducting leads to the electronic tunneling generate a superc...
0707.0495v2
2007-07-05
Adiabatic elimination in quantum stochastic models
We consider a physical system with a coupling to bosonic reservoirs via a quantum stochastic differential equation. We study the limit of this model as the coupling strength tends to infinity. We show that in this limit the solution to the quantum stochastic differential equation converges strongly to the solution of a...
0707.0686v4
2007-07-05
Solitons in interacting Dicke models of coupled cavities with two-level systems
We consider an array of coupled optical cavities, each containing a multi-atom ensemble. We show that the nonlinearity inherent in the cooperative dynamics of the atoms in each ensemble coupled to the respective cavity field allows for the formation of solitary waves. Such a prediction can be tested in state-of-the-art...
0707.0846v1
2007-07-12
Non-perturbative Yukawa Couplings from String Instantons
Non-perturbative D-brane instantons can generate perturbatively absent though phenomenologically relevant couplings for Type II orientifold compactifications with D-branes. We discuss the generation of the perturbatively vanishing SU(5) GUT Yukawa coupling of type 10 10 5_H. Moreover, for a simple globally consistent i...
0707.1871v1
2007-07-18
Oscillation of spin polarization in a two-dimensional hole gas under a perpendicular magnetic field
Spin-charge coupling is studied for a strongly confined two-dimensional hole gas subject to a perpendicular magnetic field. The study is based on spin-charge coupled drift-diffusion equations derived from quantum-kinetic equations in an exact manner. The spin-orbit interaction induces an extra out-of-plane spin polariz...
0707.2644v1
2007-07-22
Effect of a fluctuating parameter mismatch in coupled Rössler systems
This paper is concerned with the effect of parameter fluctuations with a characteristic waiting time in coupled R\"{o}ssler oscillators. We show that the averaged error in synchronization that is introduced due to a fluctuating parameter is proportional to the waiting time and the amplitude of the fluctuations. It is a...
0707.3249v1
2007-07-22
Inverse scattering in multimode structures
We consider the inverse scattering problem associated with any number of interacting modes in one-dimensional structures. The coupling between the modes is contradirectional in addition to codirectional, and may be distributed continuously or in discrete points. The local coupling as a function of position is obtained ...
0707.3252v1
2007-07-23
Linear and nonlinear optical spectroscopy of a strongly-coupled microdisk-quantum dot system
A fiber taper waveguide is used to perform direct optical spectroscopy of a microdisk-quantum-dot system, exciting the system through the photonic (light) channel rather than the excitonic (matter) channel. Strong coupling, the regime of coherent quantum interactions, is demonstrated through observation of vacuum Rabi ...
0707.3311v2
2007-07-25
Exchange shift of stripe domains in antiferromagnetically coupled multilayers
Antiferromagnetically coupled multilayers with perpendicular anisotropy, as [CoPt]/Ru, Co/Ir, Fe/Au, display ferromagnetic stripe phases as the ground states. It is theoretically shown that the antiferromagnetic interlayer exchange causes a relative shift of domains in adjacent layers. This ``exchange shift'' is respon...
0707.3765v1
2007-07-30
Temperature Dependence of Rashba Spin-orbit Coupling in Quantum Wells
We perform an all-optical spin-dynamic measurement of the Rashba spin-orbit interaction in (110)-oriented GaAs/AlGaAs quantum wells. The crystallographic direction of quantum confinement allows us to disentangle the contributions to spin-orbit coupling from the structural inversion asymmetry (Rashba term) and the bulk ...
0707.4493v1
2007-07-31
Giant magnon bound states from strongly coupled N=4 SYM
We calculate in a very simple way the spectrum of giant magnon bound states at strong coupling in N=4 SYM, by utilizing the description of the field theory vacuum in terms of a condensate of eigenvalues of commuting matrices. We further show that these calculations can be understood in terms of the central charge exten...
0707.4669v1
2007-08-04
Emergence of synchronization induced by the interplay between two prisoner's dilemma games with volunteering in small-world networks
We studied synchronization between prisoner's dilemma games with voluntary participation in two Newman-Watts small-world networks. It was found that there are three kinds of synchronization: partial phase synchronization, total phase synchronization and complete synchronization, for varied coupling factors. Besides, tw...
0708.0612v2
2007-08-07
Reliability of temporal coding on pulse-coupled networks of oscillators
We study the reliability of spike output in a general class of pulse-coupled oscillators receiving a fluctuating input. Showing that this problem is equivalent to noise-induced synchronization between identical networks of oscillators, we employ the phase reduction method to analytically derive the average Lyapunov exp...
0708.0862v1
2007-08-12
DGP Cosmology with a Non-Minimally Coupled Scalar Field on the Brane
We construct a DGP inspired braneworld scenario where a scalar field non-minimally coupled to the induced Ricci curvature is present on the brane. First we investigate the status of gravitational potential with non-minimal coupling and observational constraints on this non-minimal model. Then we further deepen the idea...
0708.1611v1
2007-08-14
Non-Minimal Inflation on the Warped DGP Brane
We construct an inflation model with inflaton non-minimally coupled to gravity on a warped DGP brane. Using an exponential potential, we calculate scalar power spectrum, spectral index and the running of the spectral index. We show that for a suitable range of non-minimal coupling it is possible to exit the inflationar...
0708.1916v2
2007-08-15
Non--Localizability of Electric Coupling and Gravitational Binding of Charged Objects
The energy--momentum tensor in general relativity contains only localized contributions to the total energy--momentum. Here, we consider a static, spherically symmetric object consisting of a charged perfect fluid. For this object, the total gravitational mass contains a non--localizable contribution of electric coupli...
0708.2037v2
2007-08-18
Synchronization in coupled phase oscillators
We make a short review about the synchronization in coupled phase oscillator models. Next, we study the common-noise-induced synchronization among active rotators. At an intermediate noise strength, the noise-induced synchronization takes place most effectively, which is analogous to the stochastic resonance. Finally, ...
0708.2460v2
2007-08-19
Coupling of electron rotation with spin in semiconductors
Account of an intrinsic spin-orbit coupling in the valence bands of common semiconductors yields the scalar spin-orbit-rotation term in the effective-mass Hamiltonian of the conduction-band electron. This result is obtained within the multiband envelope function approximation. Fundamentally, the spin-orbit-rotation cou...
0708.2565v2
2007-08-27
CP Asymmetries in Higgs decays to ZZ at the LHC
We examine the effect of a general HZZ coupling through a study of the Higgs decay to leptons via Z bosons at the LHC. We discuss various methods for placing limits on additional couplings, including measurement of the partial width, threshold scans, and asymmetries constructed from angular observables. We find that on...
0708.3612v1
2007-08-27
Diffusive-Ballistic Crossover and the Persistent Spin Helix
Conventional transport theory focuses on either the diffusive or ballistic regimes and neglects the crossover region between the two. In the presence of spin-orbit coupling, the transport equations are known only in the diffusive regime, where the spin precession angle is small. In this paper, we develop a semiclassica...
0708.3618v1
2007-08-31
ILC Sensitivity on Generic New Physics in Quartic Gauge Couplings
We investigate the potential of the ILC for measuring anomalous quartic gauge couplings, both in production of three electroweak gauge bosons as well as in vector boson scattering. Any new physics that could possibly couple to the electroweak gauge bosons is classified according to its spin and isospin quantum numbers ...
0708.4383v1
2007-09-04
Cluster Model for Near-barrier Fusion Induced by Weakly Bound and Halo Nuclei
The influence on the fusion process of coupling transfer/breakup channels is investigated for the medium weight $^{6,7}$Li+$^{59}$Co systems in the vicinity of the Coulomb barrier. Coupling effects are discussed within a comparison of predictions of the Continuum Discretized Coupled-Channels model. Applications to $^{6...
0709.0439v1
2007-09-05
Quantum Coherence Conservation by Growth in Environmental Dissipation Rate
Quantum coherence conservation is shown to be achieved by a very high rate of dissipation of an environmental system coupled with a principal system. This effect is not in the list of previously-known strategies of noise suppression, such as Zeno effect, dynamical decoupling, quantum error correction code, and decohere...
0709.0562v2
2007-09-06
Polaron tunneling dynamics in the DNA molecule
The formation of polaron and its migration in a DNA chain are studied within a semiclassical Peyrard-Biship-Holstein polaron model. Comparing the energetics of the polaron system found from the quantum chemical and semiclassical calculations, we extract the charge-phonon coupling constant for poly DNA sequences. The co...
0709.0954v1
2007-09-07
Spike synchronization of a chaotic array as a phase transition
We study how a coupled array of spiking chaotic systems synchronizes to an external driving in a short time. Synchronization means spike separation at adjacent sites much shorter than the average inter-spike interval; a local lack of synchronization is called a defect. The system displays sudden spontaneous defect disa...
0709.1108v1
2007-09-11
Bright continuous-variable entanglement from the quantum optical dimer
We show theoretically that two evanescently coupled $\chi^{(2)}$ second harmonic generators inside a Fabry-Perot cavity provide a tunable source of quadrature squeezed light, Einstein-Podolsky-Rosen correlations and quantum entanglement. Unlike systems using coupled downconverters, second harmonic generation has no osc...
0709.1533v1
2007-09-12
Quantitative 3w-Scanning Thermal Microscopy: Modelling the AC/DC coupling and the sample heat conduction
A way to increase the Scanning Thermal Microscope (SThM) sensitivity in the harmonic 3w mode is to heat the probe with an AC current sufficiently high to generate a coupling between the AC and the DC signals. We detail in this paper how to properly take into account this coupling with a Wollaston-probe SThM. We also sh...
0709.1835v1
2007-09-12
Gauge unification in noncommutative geometry
Gauge unification is widely considered to be a desirable feature for extensions of the standard model. Unfortunately the standard model itself does not exhibit a unification of its running gauge couplings but it is required by grand unified theories as well as the noncommutative version of the standard model [2]. We ...
0709.1857v1
2007-09-13
Spin polarization in biased Rashba-Dresselhaus two-dimensional electron systems
Based on spin-charge coupled drift-diffusion equations, which are derived from kinetic equations for the spin-density matrix in a rigorous manner, the electric-field-induced nonequilibrium spin polarization is treated for a two-dimensional electron gas with both Rashba and Dresselhaus spin-orbit coupling. Most emphasis...
0709.2054v1
2007-09-13
Bright branes for strongly coupled plasmas
We use holographic techniques to study photon production in a class of finite temperature, strongly coupled, large-Nc SU(Nc) quark-gluon plasmas with Nf << Nc quark flavours. Our results are valid to leading order in the electromagnetic coupling constant but non-perturbatively in the SU(Nc) interactions. The spectral f...
0709.2168v1
2007-09-24
Controlled coupling of counterpropagating whispering-gallery modes by a single Rayleigh scatterer: a classical problem in a quantum optical light
We present experiments where a single subwavelength scatterer is used to examine and control the back-scattering induced coupling between counterpropagating high-Q modes of a microsphere resonator. Our measurements reveal the standing wave character of the resulting symmetric and antisymmetric eigenmodes, their unbalan...
0709.3701v1
2007-09-28
Isotopic shift in angle-resolved photoemission spectra of Bi2Sr2CaCu2O8 due to quadratic electron-phonon coupling
In connection with the experiment on oxygen isotope effect of Bi2Sr2CaCu2O8 with the angle-resolved photoemission spectroscopy (ARPES), we theoretically study the isotope-induced band shift in ARPES by the Hartree-Fork and quantum Monte Carlo methods. We find that this band shift can be clarified based on a quadratical...
0709.4530v1
2007-10-02
Self-consistent theory of phonon renormalization and electron-phonon coupling near a 2D Kohn singularity
We show that the usual expression for evaluating electron-phonon coupling and the phonon linewidth in 2D metals with a cylindrical Fermi surface cannot be applied near the wave vector corresponding to the Kohn singularity. Instead, the Dyson equation for phonons has to be solved self-consistently. If a self-consistent ...
0710.0661v1
2007-10-11
Strong coupling expansion of Baxter equation in N=4 SYM
The anomalous dimensions of single-trace local Wilson operators with covariant derivatives in maximally supersymmetric gauge theory are believed to be generated from a deformed noncompact sl(2) Baxter equation. We perform a systematic expansion of this equation at strong coupling in the single-logarithmic limit of larg...
0710.2294v1
2007-10-12
Dimensional Reduction Applied to Non-Supersymmetric Theories
We consider regularisation of a Yang-Mills theory by Dimensional Reduction (DRED). In particular, the anomalous dimensions of fermion masses and gauge coupling are computed to four-loop order. We put special emphasis on the treatment of evanescent couplings which appear when DRED is applied to non-supersymmetric theori...
0710.2490v1
2007-10-15
Rescuing H -> bb in VBF at the LHC by requiring a central photon
The LHC potential for a measurement of the Higgs boson coupling to the b quark in the standard model is not well established yet. We show that requiring a large transverse momentum photon in the light Higgs boson production via vector-boson fusion (with subsequent H->bb decay) could provide a further handle on the Hbb ...
0710.2809v1
2007-10-16
Fano resonance in a two-level quantum dot side-coupled to leads
We theoretically study Fano resonance in a two-level quantum dot side-coupled to two leads, which are connected by a direct channel. The resonance lineshape is found to be deformed, from the conventional Fano form, by interlevel Coulomb interaction and interlevel interference. We derive the connection between the lines...
0710.3045v1
2007-10-24
Solution and Asymptotic Behavior for a Nonlocal Coupled System of Reaction-Diffusion
This paper concerns with existence, uniqueness and asymptotic behavior of the solutions for a nonlocal coupled system of reaction-diffusion. We prove the existence and uniqueness of weak solutions by the Faedo-Galerkin method and exponential decay of solutions by the classic energy method. We improve the results obtain...
0710.4381v1
2007-11-03
A coupled Volterra system and its exact solutions
A coupled Volterra system is proposed. The model can be considered as one of the integrable discrete form of the coupled integrable KdV system which is a significant physical model. Many types of cnoidal waves, positons, negatons (solitons) and complexitons of the model are obtained by a simple rational expansion metho...
0711.0420v1
2007-11-03
Bose-Fermi Equivalence in Three Dimensional Non-commutative Space-Time
We study the Fermionisation of Seiberg-Witten mapped action (to order $\theta$) of the $\lambda\phi^{4}$ theory coupled minimally with U(1) gauge field governed by Chern-Simon action. Starting from the corresponding partition function we derive non-perturbatively (in coupling constant) the partition function of the spi...
0711.0431v2
2007-11-07
Statistics of Resonances in a Semi-infinite Disordered Chain
We study the average density of resonances (DOR) for a semi-infinite disordered chain, coupled to the outside world by a (semi-infinite) perfect lead. A set of equations is derived, which provides the general framework for calculating the average DOR, for an arbitrary disorder and coupling strength. These general equat...
0711.1040v1
2007-11-09
Enhancing synchronization in complex networks of coupled phase oscillators
By a model of coupled phase oscillators, we show analytically how synchronization in {\em non-identical} complex networks can be enhanced by introducing a proper gradient into the couplings. It is found that, by pointing the gradient from the large-degree to the small-degree nodes on each link, increasing the gradient ...
0711.1409v2
2007-11-09
Persistent Current for a genus g=2 structure
We report the first calculation of persistent current in two coupled rings which form a character ``8'' genus g=2 structure. We obtain an exact solution for the persistent current and investigated the exact solution numerically. For two large coupled rings with equal fluxes, we find that the persistent current in the t...
0711.1492v2
2007-11-14
Electromagnetically induced transparency in two channels of a $Λ$ system
We show two channel electromagnetically induced transparency (EIT) spectra at various optical power. The two channels are coupling field and probe field absorption. It is shown that EIT width and intensity increases linearly with pump power. A density matrix calculation is used to determine nature of EIT spectra induce...
0711.2232v1
2007-11-15
Decoherence by a spin thermal bath: Role of the spin-spin interactions
We study the decoherence of two coupled spins that interact with a spin-bath environment. It is shown that the connectivity and the coupling strength between the spins in the environment are of crucial importance for the decoherence of the central system. Changing the connectivity or coupling strenghts changes the deco...
0711.2483v1
2007-11-15
Unitarity Bounds for New Physics from Axial Coupling at LHC
If a new massive vector boson with nonzero axial couplings to fermions will be observed at LHC, then an upper limit on the scale of new physics could be derived from unitarity of $\mathcal{S}$-matrix. The new physics will involve either new massive fermions, or scalars, or even a strongly coupled sector. We derive a mo...
0711.2516v1
2007-11-27
Exciton dephasing in quantum dots: Coupling to LO phonons via excited states
We have found a novel mechanism of spectral broadening and dephasing in quantum dots (QDs) due to the coupling to longitudinal-optical (LO) phonons. In theory, this mechanism comes into play only if the complete manifold of exciton levels (including those in the wetting-layer continuum) is taken into account. We demons...
0711.4274v1
2007-11-27
Absolute Continuity of the Integrated Density of States for the Almost Mathieu Operator with Non-Critical Coupling
We show that the integrated density of states of the almost Mathieu operator is absolutely continuous if and only if the coupling is non-critical. We deduce for subcritical coupling that the spectrum is purely absolutely continuous for almost every phase, settling the measure-theoretical case of Problem 6 of Barry Simo...
0711.4291v1
2007-11-27
A Simple Baryon Triality Model for Neutrino Masses
We make a simple ansatz for the supersymmetric lepton-number violating Yukawa couplings, by relating them to the corresponding Higgs Yukawa couplings. This reduces the free B$_3$ parameters from 36 to 6. We fit these parameters to solve the solar and atmospheric neutrino anomalies in terms of neutrino oscillations. The...
0711.4315v1
2007-12-07
First Calculation of Hyperon Axial Couplings from Lattice QCD
In this work, we report the first lattice calculation of hyperon axial couplings, using the 2+1-flavor MILC configurations and domain-wall fermion valence quarks. Both the $\Sigma$ and $\Xi$ axial couplings are computed for the first time in lattice QCD. In particular we find that $g_{\Sigma\Sigma} = 0.450(21)_{\rm sta...
0712.1214v1
2007-12-14
Heralded generation of entanglement with coupled cavities
We propose a scheme to generate two-photon, two-atom, or atom-photon entangledstates with a coupled system of two cavities. In our scheme, two cavity photonsare exchanged by the direct inter-cavity coupling, while atoms in the cavitiessimply play the role of generating and probing them. By virtue of the highefficiency ...
0712.2413v2
2007-12-17
A Generalized Scaling Function for AdS/CFT
We study a refined large spin limit for twist operators in the sl(2) sector of AdS/CFT. We derive a novel non-perturbative equation for the generalized two-parameter scaling function associated to this limit, and analyze it at weak coupling. It is expected to smoothly interpolate between weakly coupled gauge theory and...
0712.2743v2
2007-12-26
Observation of all-optical bump-on-tail instability
We demonstrate an all-optical bump-on-tail instability by considering the nonlinear interaction of two partially-coherent spatial beams. For weak wave coupling, we observe momentum transfer with no variation in intensity. For strong wave coupling, modulations appear in intensity and evidence appears for wave (Langmuir)...
0712.4128v1
2007-12-30
Fundamental excitations in layered superconductors with long-range Josephson couplings
The present paper develops the ideas introduced in {\em cond-mat/0312673}. The construction of a hybrid discrete-continuous model of layered superconductors is briefly presented. The model bases on the classic Lawrence-Doniach scenario with admitting, however, long-range interactions between atomic planes. Moreover, ap...
0801.0171v1
2008-01-03
"Light from chaos" in two dimensions
We perform a Monte-Carlo study of the lattice two-dimensional gauged XY-model. Our results confirm the strong-coupling expansion arguments that for sufficiently small values of the spin-spin coupling the ``gauge symmetry breaking" terms decouple and the long-distance physics is that of the unbroken pure gauge theory. W...
0801.0587v1
2008-01-07
A New Methodology for Extraction of Dynamic Compact Thermal Models
An innovative and accurate dynamic Compact Thermal Model extraction method is proposed for multi-chip power electronics systems. It accounts for thermal coupling between multiple heat sources. Transient electro-thermal coupling can easily be taken into account by system designers. The method is based on a definition of...
0801.1044v1
2008-01-08
Optimal co-adapted coupling for the symmetric random walk on the hypercube
Let X and Y be two simple symmetric continuous-time random walks on the vertices of the n-dimensional hypercube. We consider the class of co-adapted couplings of these processes, and describe an intuitive coupling which is shown to be the fastest in this class.
0801.1220v2
2008-01-10
A Lorentz Invariant Pairing Mechanism: Relativistic Cooper Pairs
We study a Lorentz invariant pairing mechanism that arises when two relativistic spin-1/2 fermions are subjected to a Dirac string coupling. In the weak coupling regime, we find remarkable analogies between this relativistic bound system and the well known superconducting Cooper pair. As the coupling strength is raised...
0801.1615v1
2008-01-14
Spin-Gravity Coupling
Mathisson's spin-gravity coupling and its Larmor-equivalent interaction, namely, the spin-rotation coupling are discussed. The study of the latter leads to a critical examination of the basic role of locality in relativistic physics. The nonlocal theory of accelerated systems is outlined and some of its implications ar...
0801.2134v1
2008-01-18
Synchronizing discrete-time neutrally stable linear systems via partial-state coupling
A basic result in synchronization of linear systems via output coupling is presented. For identical discrete-time linear systems that are detectable from their outputs and neutrally stable, it is shown that a linear output feedback law exists under which the coupled systems globally asymptotically synchronize for all f...
0801.2945v2
2008-01-20
Orbital magnetization and its effects in spin-chiral ferromagnetic kagome lattice in the general spin-coupling region
The orbital magnetization and its effects on the two-dimensional kagom\'{e} lattice with spin anisotropies included in the general Hund's coupling region have been theoretically studied. The results show that the strength of the Hund's coupling, as well as the spin chirality, contributes to the orbital magnetization $\...
0801.3061v1
2008-01-21
Synchronizing continuous-time neutrally stable linear systems via partial-state coupling
Synchronization of coupled continuous-time linear systems is studied in a general setting. For identical neutrally-stable linear systems that are detectable from their outputs, it is shown that a linear output feedback law exists under which the coupled systems globally asymptotically synchronize under all fixed (direc...
0801.3185v1
2008-01-29
Shear viscosity of boost invariant plasma at finite coupling
We discuss string theory alpha' corrections in the dual description of the expanding boost invariant N=4 supersymmetric Yang-Mills plasma at strong coupling. We compute finite 't Hooft coupling corrections to the shear viscosity and find that it disagrees with the equilibrium correlation function computations. We comme...
0801.4421v2
2008-01-31
Discrete symmetries of chaotic strings
Chaotic strings are particular classes of coupled map lattices that can serve as models for vacuum fluctuations in stochastically quantized field theories. They have been previously shown to distinguish standard model coupling parameters as corresponding to states of strongest possible chaotic behaviour and vanishing n...
0801.4892v1
2008-01-31
Non-adiabatic two-parameter charge and spin pumping in a quantum dot
We study DC charge and spin transport through a weakly coupled quantum dot, driven by a non-adiabatic periodic change of system parameters. We generalize the model of Tien and Gordon to simultaneously oscillating voltages and tunnel couplings. When applying our general result to the two-parameter charge pumping in quan...
0801.4925v1
2008-02-03
(Ga,Mn)As based superlattices and the search for antiferromagnetic interlayer coupling
Antiferromagnetic interlayer coupling in dilute magnetic semiconductor superlattices could result in the realisation of large magnetoresistance effects analogous to the giant magnetoresistance seen in metallic multilayer structures. In this paper we use a mean-field theory of carrier induced ferromagnetism to explore t...
0802.0275v2
2008-02-06
Synchronization between variable time delayed systems and cryptography
In this letter we consider a prototype model which is described as an autonomous continuous time delayed differential equation with just one variable. The chaos has been investigated with variable delay time and the synchronization phenomenon is examined both numerically and analytically using the Krasovskii-Lyapunov f...
0802.0768v1