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2022-11-07
Mirror-coupled plasmonic bound states in the continuum for tunable perfect absorption
Tailoring critical light-matter coupling is a fundamental challenge of nanophotonics, impacting diverse fields from higher harmonic generation and energy conversion to surface-enhanced spectroscopy. Plasmonic perfect absorbers (PAs), where resonant antennas couple to their mirror images in adjacent metal films, have be...
2211.03673v1
2022-11-18
Normalized solution to coupled nonhomogeneous nonlinear elliptic system with three wave interaction under unbounded potentials
In this paper, we use the variational method to find the normalized solutions of the quadratic coupled three wave Schrodinger equation with asymmetric coercive potential. We prove the existence of solutions for the system with 2-norm constraints.
2211.10110v1
2022-12-12
A universal and stable metasurface for photonic quasi bound state in continuum coupled with two dimensional semiconductors
Strong coupling of excitons to optical cavity modes is of immense importance to understanding the fundamental physics of quantum electrodynamics at the nanoscale as well as for practical applications in quantum information technologies. There have been several attempts at achieving strong coupling between excitons in t...
2212.05951v1
2022-12-12
Efficient simulation of open quantum systems coupled to a reservoir through multiple channels
The simulation of open quantum systems coupled to a reservoir through multiple channels remains a substantial challenge. This kind of open quantum system arises when considering the radiationless decay of excited states that are coupled to molecular vibrations, for example. We use the chain mapping strategy in the inte...
2212.06099v1
2023-01-05
A Minimization Problem with Free Boundary for $p$-Laplacian weakly coupled System
In this paper we consider a weakly coupled $p$-Laplacian system of a Bernoulli type free boundary problem, through minimization of a corresponding functional. We prove various properties of any local minimizer and the corresponding free boundary.
2301.02236v1
2023-02-17
Multi-scalar theories of gravity with direct matter couplings and their parametrized post-Newtonian parameters
We study theories of gravity including, in addition to the metric, several scalar fields in the gravitational sector. The particularity of this work is that we allow for direct couplings between these gravitating scalars and the matter sector, which can generally be different for the source and the probe of gravity, in...
2302.08941v2
2023-03-12
Banach Couples. I. Elementary Theory
This note is an (exact) copy of the report of Jaak Peetre, "Banach Couples. I. Elementary Theory". Published as Technical Report, Lund (1971). Some more recent general references have been added and some references updated though
2303.06622v1
2023-03-13
Modifying the magnetoelectric coupling in TbMnO$_3$ by low-level Fe$^{3+}$ substitution
We report a comprehensive study of the low-level substitution of Mn$^{3+}$ by Fe$^{3+}$ effect on the static and dynamic magnetoelectric coupling in TbMn$_{1-x}$Fe$_x$O$_3$ ($x=0$, 0.02 and 0.04). The cationic substitution has a large impact on the balance between competitive magnetic interactions and, as a result, on ...
2303.07029v1
2023-03-15
ROSE: A Neurocomputational Architecture for Syntax
A comprehensive model of natural language processing in the brain must accommodate four components: representations, operations, structures and encoding. It further requires a principled account of how these components mechanistically, and causally, relate to each another. While previous models have isolated regions of...
2303.08877v1
2023-03-17
One-loop beta-functions of quartic enhanced tensor field theories
Enhanced tensor field theories (eTFT) have dominant graphs that differ from the melonic diagrams of conventional tensor field theories. They therefore describe pertinent candidates to escape the so-called branched polymer phase, the universal geometry found for tensor models. For generic order $d$ of the tensor field, ...
2303.09829v3
2023-04-11
Investigation of the concurrent effects of ALP-photon and ALP-electron couplings in Collider and Beam Dump Searches
Axion-like particles (ALPs) have been studied in numerous experiments to search for their interactions, but most studies have focused on deriving bounds for the single coupling. However, in ultraviolet (UV) models, these couplings can appear simultaneously, and their interplay could have important implications for coll...
2304.05435v2
2023-04-16
Analysis of strong coupling constant with machine learning and its application
In this work, we investigate the nature of the strong coupling constant and related physics. Through the analysis of accumulated experimental data from around the world, we employ the ability of machine learning to unravel its physical laws. The result of our efforts is a formula that captures the expansive panorama of...
2304.07682v4
2023-05-07
Higher-Order Network Interactions through Phase Reduction for Oscillators with Phase-Dependent Amplitude
Coupled oscillator networks provide mathematical models for interacting periodic processes. If the coupling is weak, phase reduction -- the reduction of the dynamics onto an invariant torus -- captures the emergence of collective dynamical phenomena, such as synchronization. While a first-order approximation of the dyn...
2305.04277v2
2023-05-27
Flavor Violating Di- Higgs Coupling
Di-Higgs couplings to fermions of the form $h^{2}\overline{f}f$ are absent in the Standard Model, however, they are present in several physics Beyond Standard Model (BSM) extensions, including those with vector-like fermions. In Effective Field Theories (EFTs), such as the Standard Model Effective Field Theory (SMEFT) ...
2305.17362v1
2023-06-16
System-bath entanglement of noninteracting fermionic impurities: Equilibrium, transient, and steady-state regimes
We investigate the behavior of entanglement between a single fermionic level and a fermionic bath in three distinct thermodynamic regimes. First, in thermal equilibrium, we analyze the dependence of entanglement on the considered statistical ensemble: for the grand canonical state, it is generated only for a sufficient...
2306.09680v3
2023-07-21
Observation of strong coupling between a mechanical oscillator and a cavity-magnon polariton
Cavity magnomechanics (CMM) is an emerging field and has received much attention in the past decade. It deals with coherent couplings among microwave cavity photons, magnons and vibration phonons. So far, all previous CMM experiments have been operated in the weak-coupling regime. This considerably limits prospective v...
2307.11328v2
2023-08-03
Microscopic Gyration with Dissipative Coupling
Microscopic gyrators, including Brownian gyrators (BGs), require anisotropic fluctuations to perform gyration. It produces a finite current, driving the system out of equilibrium. In a typical BG set-up with an isotropic colloidal particle, the anisotropy sets in by the coupling among space dimensions via an externally...
2308.02085v1
2023-08-09
Understanding the Nature of Vibro-Polaritonic States in Water and Heavy Water
One of the most popular subjects now being researched in molecular science is strong light-matter coupling. The introduction of vibrational strong coupling and the formation vibro-polaritonic states tend to modify chemical reactivity, energy transfer, and many other physical properties of the coupled system. This is ac...
2308.04777v1
2023-08-09
Strong Exciton-Phonon Coupling as a Fingerprint of Magnetic Ordering in van der Waals Layered CrSBr
The layered, air-stable van der Waals antiferromagnetic compound CrSBr exhibits pronounced coupling between its optical, electronic, and magnetic properties. As an example, exciton dynamics can be significantly influenced by lattice vibrations through exciton-phonon coupling. Using low-temperature photoluminescence spe...
2308.04895v2
2023-09-25
Observational constraints on interactions between dark energy and dark matter with momentum and energy transfers
We place observational constraints on a dark energy (DE) model in which a quintessence scalar field $\phi$ is coupled to dark matter (DM) through momentum and energy exchanges.The momentum transfer is weighed by an interaction between the field derivative and DM four velocity with a coupling constant $\beta$, whereas t...
2309.13946v2
2023-10-12
A note on balance laws of coupled surface and bulk fluid flows
Balance laws of coupled bulk-surface-bulk fluid flows are considered. We carefully investigate how do the interface conditions influence the total mass, total momentum and total energy of the system.
2310.08688v1
2023-10-31
Experimental probes and theoretical concepts for BSM trilinear couplings: a case study for scalar top quarks
After the possible discovery of new particles, it will be crucial to determine the properties, and in particular the couplings, of the new states. Here, we focus on scalar trilinear couplings, employing as an example the case of the trilinear coupling of scalar top quarks (stops) to the Higgs boson in the Minimal Super...
2310.20655v1
2023-11-01
Analysis of the Single Reference Coupled Cluster Method for Electronic Structure Calculations: The Discrete Coupled Cluster Equations
Coupled cluster methods are widely regarded as the gold standard of computational quantum chemistry as they are perceived to offer the best compromise between computational cost and a high-accuracy resolution of the ground state eigenvalue of the electronic Hamiltonian -- an unbounded, self-adjoint operator acting on a...
2311.00637v2
2023-11-05
Topological spin-orbit-coupled fermions beyond rotating wave approximation
The realization of spin-orbit-coupled ultracold gases has driven a wide range of researches and is typically based on the rotating wave approximation (RWA). By neglecting the counter-rotating terms, RWA characterizes a single near-resonant spin-orbit (SO) coupling in a two-level system. Here, we propose and experimenta...
2311.02584v1
2023-11-24
Coupled Twiss Parameters Estimation from TbT Data
Linear optics parameters are often estimated using readily available turn-by-turn (TbT) data. In-plane beta functions, which are the most common measurement objectives, can be estimated from the amplitudes or phases of TbT data, providing an overall characterization of the linear lattice. In addition to estimating unco...
2311.14287v2
2023-12-08
Enhanced quantum sensing mediated by a cavity in open systems
We simulate the dynamics of systems with $N$ = 1-20 qubits coupled to a cavity in order to assess their potential for quantum metrology of a parameter in the open systems limit. The qubits and the cavity are both allowed to have losses and the system is studied under various coupling strength regimes. The focus is prim...
2312.04766v1
2024-01-03
Single-photon scattering in giant-atom waveguide systems with chiral coupling
We study single-photon scattering spectra of a giant atom chirally coupled to a one-dimensional waveguide at multiple connection points, and examine chirality induced effects in the scattering spectra by engineering the chirality of the coupling strengths. We show that the transmission spectra typically possess an anti...
2401.01592v1
2024-01-09
Electronic effects in radiation-induced collision cascades in nickel
The accurate treatment of electronic effects in multi-million atom simulations of radiation-induced collision cascades is crucial for reliable predictions of primary radiation damage. In this work, we explore the performance of a recently developed two-temperature molecular dynamics model implementing an electron densi...
2401.04404v1
2023-12-24
Deep Pulse-Coupled Neural Networks
Spiking Neural Networks (SNNs) capture the information processing mechanism of the brain by taking advantage of spiking neurons, such as the Leaky Integrate-and-Fire (LIF) model neuron, which incorporates temporal dynamics and transmits information via discrete and asynchronous spikes. However, the simplified biologica...
2401.08649v1
2024-01-19
An Experimental Estimation Method of Diffusion Coefficients in Ternary and Multicomponent Systems from a Single Diffusion Couple Profile
Until recently, it was textbook knowledge that the diffusion coefficients could not be estimated in a multi-component system following the widely practised diffusion couple method. The recently proposed constrained diffusion couple methods need two intersecting diffusion paths in a multi-component space with very well-...
2401.10684v1
2024-01-22
Gravitational collapse of matter in the presence of non-minimally coupled Quintessence and Phantom-like scalar fields
This paper explores the evolution of the over-dense region of dark matter in the presence of a non-minimally coupled scalar field which is used to model quintessence and phantom-like dark energy. We focus on algebraic coupling, where the interaction Lagrangian is independent of the derivatives of the scalar field. To m...
2401.11957v1
2024-02-19
Description of ultrastrong light-matter interaction through coupled harmonic oscillator models and their connection with cavity-QED Hamiltonians
Classical coupled harmonic oscillator models have been proven capable to describe successfully the spectra of many nanophotonic systems where an optical mode couples to a molecular or matter excitation. Although models with distinct coupling terms have been proposed, they are used interchangeably due to their similar r...
2402.11944v1
2024-02-26
Strong coupling yields abrupt synchronization transitions in coupled oscillators
Coupled oscillator networks often display transitions between qualitatively different phase-locked solutions -- such as synchrony and rotating wave solutions -- following perturbation or parameter variation. In the limit of weak coupling, these transitions can be understood in terms of commonly studied phase approximat...
2402.16471v1
2024-03-10
Coupled Dislocations and Fracture dynamics at finite deformation: model derivation, and physical questions
A continuum mechanical model of coupled dislocation based plasticity and fracture at finite deformation is proposed. Motivating questions and target applications of the model are sketched.
2403.06061v2
2024-03-26
Shape Optimization of Geometrically Nonlinear Modal Coupling Coefficients: An Application to MEMS Gyroscopes
Micro- and nanoelectromechanical system (MEMS and NEMS) resonators can exhibit rich nonlinear dynamics as they are often operated at large amplitudes with high quality factors and possess a high mode density with a variety of nonlinear modal couplings. Their impact is strongly influenced by internal resonance condition...
2403.17679v1
2024-04-05
Nonlocally coupled moisture model for convective self-aggregation
Clouds play a central role in climate physics by interacting with precipitation, radiation, and circulation. Although the self-aggregation of clouds is a fundamental problem in convective organization, a theoretical explanation of how it occurs has not been established owing to its complexity. Here, we introduce an ide...
2404.04146v1
2024-04-08
On a port-Hamiltonian formulation and structure-preserving numerical approximations for thermodynamic compressible fluid flow
The high volatility of renewable energies calls for more energy efficiency. Thus, different physical systems need to be coupled efficiently although they run on various time scales. Here, the port-Hamiltonian (pH) modeling framework comes into play as it has several advantages, e.g., physical properties are encoded in ...
2404.05358v1
1999-02-08
Non-linear coupling of spiral waves in disk galaxies: a numerical study
We present the results of two-dimensional numerical simulations of stellar galactic disks, aimed at studying the non-linear coupling between bar and spiral waves and modes, in disks with realistically peaked rotation profiles. The power spectrum analysis of the perturbed density in the disk, for azimuthal numbers rangi...
9902125v1
1999-08-03
Coupled Quintessence
A new component of the cosmic medium, a light scalar field or ''quintessence '', has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant. Such a field is expected to be coupled explicitely to ordinary matter, unless some unknown symmetry prevents it. I investigate the cosmologic...
9908023v1
2001-04-30
Perturbation evolution with a non-minimally coupled scalar field
We recently proposed a simple dilaton-derived quintessence model in which the scalar field was non-minimally coupled to cold dark matter, but not to `visible' matter. Such couplings can be attributed to the dilaton in the low energy limit of string theory, beyond tree level. In this paper we discuss the implications of...
0104464v4
2002-04-30
Quintessence, super-quintessence and observable quantities in Brans-Dicke and non-minimally coupled theories
The different definitions for the equation of state of a non-minimally coupled scalar field that have been introduced in the literature are analyzed. Particular emphasis is made upon those features that could yield to an observable way of distinguishing non-minimally coupled theories from General Relativity, with the s...
0204504v2
2006-01-16
Constraints on the coupled quintessence from cosmic microwave background anisotropy and matter power spectrum
We discuss the evolution of linear perturbations in a quintessence model in which the scalar field is non-minimally coupled to cold dark matter. We consider the effects of this coupling on both cosmic microwave background temperature anisotropies and matter perturbations. Due to the modification of the scale of cold da...
0601333v1
1994-11-06
M-furcations in coupled maps
We study the scaling behavior of $M$-furcation $(M\!=\!2, 3, 4,\dots)$ sequences of $M^n$-period $(n=1,2,\dots)$ orbits in two coupled one-dimensional (1D) maps. Using a renormalization method, how the scaling behavior depends on $M$ is particularly investigated in the zero-coupling case in which the two 1D maps become...
9411003v1
1996-12-05
Synchronization of Spatiotemporal Chaos: The regime of coupled Spatiotemporal Intermittency
Synchronization of spatiotemporally chaotic extended systems is considered in the context of coupled one-dimensional Complex Ginzburg-Landau equations (CGLE). A regime of coupled spatiotemporal intermittency (STI) is identified and described in terms of the space-time synchronized chaotic motion of localized structures...
9612011v1
1994-04-26
Relation of Extended Van Hove Singularities to High-Temperature Superconductivity within Strong-Coupling Theory
Recent angle-resolved photoemission (ARPES) experiments have indicated that the electronic dispersion in some of the cuprates possesses an extended saddle point near the Fermi level which gives rise to a density of states that diverges like a power law instead of the weaker logarithmic divergence usually considered. We...
9404081v1
1994-05-16
Spin Gaps in Coupled t-J Ladders
Spin gaps in coupled $t$-$J$ ladders are investigated by exact diagonalization of small clusters up to 4$\times$8 sites. At half-filling, the numerical results for the triplet excitation spectrum are in very good agreement with a second order perturbation expansion in term of small inter-ladder and intra-ladder exchang...
9405045v1
1995-10-06
Van Hove Exciton-Cageons and High-T$_c$ Superconductivity: XB: Polaronic Coupling in the Doped Material
A purely ionic interpretation of the tilting mode instabilities in La$_{2-x}$A$ _x$CuO$_4$ (A=Sr,Ba) is shown to be not self-consistent: the dominant factor influencing the doping dependence of the interlayer mismatch is the large change in the Cu-O bond length, which in turn leads to a strong electron-phonon coupling....
9510034v1
1995-10-26
Properties of lightly doped t-J two-leg ladders
We have numerically investigated the doped t-J ladder using exact diagonalization. We have studied both the limit of strong inter-chain coupling and isotropic coupling. The ladder scales to the Luther-Emery liquid regime in the strong inter-chain coupling limit. In this strong coupling limit there is a simple picture o...
9510150v1
1997-10-16
Hole doping and disorder effects on the one-dimensional Kondo lattice, for ferromagnetic Kondo couplings
We investigate the one-dimensional Kondo lattice model (1D KLM) for ferromagnetic Kondo couplings. The so-called ferromagnetic 2-leg spin ladder and the S=1 antiferromagnet occur as new one-dimensional Kondo insulators. Both exhibit a spin gap. But, in contrast to the strong coupling limit, the Haldane state which char...
9710166v1
1998-05-04
A Renormalization Group Study of Asymetrically Coupled Minimal Models
We investigate the renormalization group flows and fixed point structure of many coupled minimal models. The models are coupled two by two by energy-energy couplings. We take the general approach where the bare couplings are all taken to be independent. New fixed points are found for N models (N>3). At these fixed poin...
9805026v1
1998-07-06
The XY Spin-Glass with Slow Dynamic Couplings
We investigate an XY spin-glass model in which both spins and couplings evolve in time: the spins change rapidly according to Glauber-type rules, whereas the couplings evolve slowly with a dynamics involving spin correlations and Gaussian disorder. For large times the model can be solved using replica theory. In contra...
9807082v1
1998-07-23
The optical response of Ba_{1-x}K_xBiO_3: Evidence for an unusual coupling mechanism of superconductivity?
We have analysed optical reflectivity data for Ba_{1-x}K_xBiO_3 in the far-infrared region using Migdal-Eliashberg theory and found it inconsistent with standard electron-phonon coupling: Whereas the superconducting state data could be explained using moderate coupling, \lambda=0.7, the normal state properties indicate...
9807314v1
1998-08-27
Mean-Field Theory for Spin Ladders Using Angular-Momentum Coupled Bases
We study properties of two-leg Heisenberg spin ladders in a mean-field approximation using a variety of angular-momentum coupled bases. The mean-field theory proposed by Gopalan, Rice, and Sigrist, which uses a rung basis, assumes that the mean-field ground state consists of a condensate of spin-singlets along the rung...
9808310v1
1999-09-09
Superexchange via Cluster States: Calculations of Spin-Phonon Coupling Constants for CuGeO3
Calculations for spin-phonon coupling constants in CuGeO3 are presented, applying fourth order superexchange perturbation theory to an extended Hubbard model. In our treatment, the intermediate oxygen ligand states are described by band-like cluster states, due to the presence of significant O(p)-O(p) hopping. We also ...
9909134v1
1999-10-07
Spin interactions and switching in vertically tunnel-coupled quantum dots
We determine the spin exchange coupling J between two electrons located in two vertically tunnel-coupled quantum dots, and its variation when magnetic (B) and electric (E) fields (both in-plane and perpendicular) are applied. We predict a strong decrease of J as the in-plane B field is increased, mainly due to orbital ...
9910105v1
1999-11-29
Spike-train responses of a pair of Hodgkin-Huxley neurons coupled by excitatory and inhibitory synapses and axons with time delay
Numerical calculations have been made on the spike-train response of a pair of Hodgkin-Huxley (HH) neurons coupled by synapses and axons with time delay. The recurrent excitatory-excitatory, inhibitory-inhibitory, excitatory-inhibitory, and inhibitory-excitatory couplings are adopted. The coupled, excitable HH neurons ...
9911472v1
1999-12-23
Phonon-Coupled Electron Tunneling in Two and Three-Dimensional Tunneling Configurations
We treat a tunneling electron coupled to acoustical phonons through a realistic electron phonon interaction: deformation potential and piezoelectric, in two or three-dimensional tunneling configurations. Making use of slowness of the phonon system compared to electron tunneling, and using a Green function method for im...
9912427v1
2001-05-21
Calculation of mode coupling for quadrupole excitations in a Bose-Einstein condensate
In this paper we give a theoretical description of resonant coupling between two collective excitations of a Bose condensed gas (BEC) on, or close, to a second harmonic resonance. Using analytic expressions for the quasi-particle wavefunctions we show that the coupling between quadrupole modes is strong, leading to a c...
0105394v1
2001-09-19
Synchronous phase clustering in a network of neurons with spatially decaying excitatory coupling
Synchronization is studied in a spatially-distributed network of weekly-coupled, excitatory neurons of Hodgkin-Huxley type. All neurons are coupled to each other synaptically with a fixed time delay and a coupling strength inversely proportional to the distance between two neurons. We found that a robust, noise-resista...
0109332v1
2002-02-08
BEDT-TTF organic superconductors: the entangled role of phonons
We calculate the lattice phonons and the electron-phonon coupling of the organic superconductor \kappa-(BEDT-TTF)_2 I_3, reproducing all available experimental data connected to phonon dynamics. Low-frequency intra-molecular vibrations are strongly mixed to lattice phonons. Both acoustic and optical phonons are appreci...
0202141v3
2003-02-11
Peierls transition in the presence of finite-frequency phonons in the one-dimensional extended Peierls-Hubbard model at half-filling
We report quantum Monte Carlo (stochastic series expansion) results for the transition from a Mott insulator to a dimerized Peierls insulating state in a half-filled, 1D extended Hubbard model coupled to optical bond phonons. Using electron-electron (e-e) interaction parameters corresponding approximately to polyacetyl...
0302220v1
2003-02-17
Structural Aspects of Magnetic Coupling in CaCu3Mn4O12 and CaCu3Ti4O12
Two perovskite-derived materials, CaCu3Mn4O12 and CaCu3Ti4O12, have drawn much recent interest due to their magnetoresistive, dielectric, and magnetoelectronic characteristics. Here we present initial theoretical insights into each of these points, based on first principles, density functional based calculations. Our r...
0302343v1
2003-05-28
Strong Coupling Expansion for the Pairing Hamiltonian
The paper is devoted to the effects of superconducting pairing in small metallic grains. It turns out that at strong superconducting coupling and in the limit of large Thouless conductance one can explicitly determine the low energy spectrum of the problem. We start with the strong coupling limit and develop a systemat...
0305635v1
2003-06-11
Density matrix renormalization group study of the charging of a quantum dot strongly coupled to a single lead
A new application of the density matrix renormalization group (DMRG) method to a system composed of an interacting dot coupled to a infinite one dimensional lead is presented. This method enables one to study the influence of the coupling to an external lead on the thermodynamical properties of the dot. It is shown tha...
0306284v1
2003-07-07
Quasistates in a ring coupled to a reservoir and their relation to the Dicke effect
We study the energy spectrum and the persistent current in an ideal one-dimensional mesoscopic ring coupled to an external fermionic reservoir. The contact between ring and reservoir is described by a tunneling operator, which causes an indirect coupling between different ring states via states in the reservoir. For st...
0307136v1
2003-07-30
Neel to spin-Peierls transition in the ground state of a quasi-1D Heisenberg model coupled to bond phonons
The spin-Peierls transition in the ground state of a quasi-one-dimensional spin-1/2 Heisenberg model coupled to adiabatic bond phonons is studied using a quantum Monte Carlo (QMC) method. The transition from a gapless Neel state to a spin-gapped Peierls state is explored in the parameter space spanned by the spatial an...
0307746v1
2004-01-15
Ferrimagnetic mixed-spin ladders in weak and strong coupling limits
We study two similar spin ladder systems with the ferromagnetic leg coupling. First model includes two sorts of spins, s= 1/2 and s= 1, and the second model comprises only s=1/2 legs coupled by a "triangular" rung exchange. The antiferromagnetic (AF) rung coupling destroys the long-range order and eventually makes the ...
0401264v2
2004-04-01
Electronic Structure and Electron-Phonon Coupling in the 18K Superconductor Y2C3
The electronic structure and electron-phonon coupling in Y2C3 is investigated using density functional calculations. We find that the Fermi level falls in a manifold of mixed character derived from Y d states and antibonding states associated with the C dimers in the structure. Calculations of the electron-phonon coupl...
0404031v1
2004-05-26
Vortex in Maxwell-Chern-Simons models coupled to external backgrounds
We consider Maxwell-Chern-Simons models involving different non-minimal coupling terms to a non relativistic massive scalar and further coupled to an external uniform background charge. We study how these models can be constrained to support static radially symmetric vortex configurations saturating the lower bound for...
0405605v1
2004-06-08
Enhancing complex-network synchronization
Heterogeneity in the degree (connectivity) distribution has been shown to suppress synchronization in networks of symmetrically coupled oscillators with uniform coupling strength (unweighted coupling). Here we uncover a condition for enhanced synchronization in directed networks with weighted coupling. We show that, in...
0406207v1
2004-07-26
Quantum computation with Josephson-qubits by using a current-biased information bus
We propose an effective scheme for manipulating quantum information stored in a superconducting nanocircuit. The Josephson qubits are coupled via their separate interactions with an information bus, a large current-biased Josephson junction treated as an oscillator with adjustable frequency. The bus is sequentially cou...
0407667v2
2004-10-08
van der Waals coupling in atomically doped carbon nanotubes
We have investigated atom-nanotube van der Waals (vdW) coupling in atomically doped carbon nanotubes (CNs). Our approach is based on the perturbation theory for degenerated atomic levels, thus accounting for both weak and strong atom-vacuum-field coupling. The vdW energy is described by an integral equation represented...
0410216v1
2005-01-07
Long Josephson Junction in a Resonant Cavity
We present a model to describe an underdamped long Josephson junction coupled to a singlemode electromagnetic cavity, and carry out numerical calculations using this model in various regimes. The coupling may occur through either the electric or the magnetic eld of the cavity mode. When a current is injected into the j...
0501147v1
2005-01-18
Phase diagram of the one-dimensional, two-channel Kondo lattice model
Employing the density matrix renormalization group method and strong-coupling perturbation theory, we study the phase diagram of the SU(2)xSU(2) Kondo lattice model in one dimension. We show that, at quarter filling, the system can exist in two phases depending on the coupling strength. The weak-coupling phase is domin...
0501430v1
2005-01-22
Asymmetrically coupled directed percolation systems
We introduce a dynamical model of coupled directed percolation systems with two particle species. The two species $A$ and $B$ are coupled asymmetrically in that $A$ particles branch $B$ particles whereas $B$ particles prey on $A$ particles. This model may describe epidemic spreading controlled by reactive immunization ...
0501542v1
2005-05-30
Charge order induced by electron-lattice interaction in NaV2O5
We present Density Matrix Renormalization Group calculations of the ground-state properties of quarter-filled ladders including static electron-lattice coupling. Isolated ladders and two coupled ladders are considered, with model parameters obtained from band-structure calculations for $\alpha^\prime$-NaV$_2$O$_5$. The...
0505685v1
2005-06-10
Extension of Frohlich's method to 4-fermion interactions
Higher order terms of the transformed electron-phonon Hamiltonian, obtained by performing the Frohlich's transformation, are investigated. The influence of terms discarded by Frohlich (in particular those proportional to the third power of electron-phonon coupling) on the effective Hamiltonian is examined. To this end ...
0506248v2
2005-07-18
Coupled ferro-antiferromagnetic Heisenberg bilayers investigated by many-body Green's function theory
A theory of coupled ferro- and antiferromagnetic Heisenberg layers is developed within the framework of many-body Green's function theory (GFT) that allows non-collinear magnetic arrangements by introducing sublattice structures. As an example, the coupled ferro- antiferromagnetic (FM-AFM) bilayer is investigated. We c...
0507408v1
2006-02-23
Ion implanted Si:P double-dot with gate tuneable interdot coupling
We report on millikelvin charge sensing measurements of a silicon double-dot system fabricated by phosphorus ion implantation. An aluminum single-electron transistor (SET) is capacitively coupled to each of the implanted dots enabling the charging behavior of the double-dot system to be studied independently of current...
0602538v1
2006-02-23
Electron transport through Aharonov-Bohm interferometer with laterally coupled double quantum dots
We theoretically investigate electron transport through an Aharonov-Bohm interferometer containing laterally coupled double quantum dots. We introduce the indirect coupling parameter $\alpha$, which characterizes the strength of the coupling via the reservoirs between two quantum dots. $|\alpha|=1$ indicates the strong...
0602539v2
2006-03-02
Vertically coupled double quantum rings at zero magnetic field
Within local-spin-density functional theory, we have investigated the `dissociation' of few-electron circular vertical semiconductor double quantum ring artificial molecules at zero magnetic field as a function of inter-ring distance. In a first step, the molecules are constituted by two identical quantum rings. When t...
0603040v1
2006-06-21
Strong Electron-Phonon Coupling in Yttrium under Pressure
Linear response methods are applied to identify the increase in electron-phonon coupling in elemental yttrium that is responsible for its high superconducting critical temperature Tc, which reaches nearly 20 K at 115 GPa. While the evolution of the band structure and density of states is smooth and seemingly modest, th...
0606538v1
2006-07-03
Transport through two-level quantum dots weakly coupled to ferromagnetic leads
Spin-dependent transport through a two-level quantum dot in the sequential tunneling regime is analyzed theoretically by means of a real-time diagrammatic technique. It is shown that the current, tunnel magnetoresistance, and shot noise (Fano factor) strongly depend on the transport regime, providing a detailed informa...
0607039v3
2006-07-07
Controllable Coupling between Flux Qubit and Nanomechanical Resonator by Magnetic Field
We propose an active mechanism for coupling the quantized mode of a nanomechanical resonator to the persistent current in the loop of a superconducting Josephson junction (or phase slip) flux qubit. This coupling is independently controlled by an external coupling magnetic field. The whole system forms a novel solid-st...
0607180v2
2006-10-19
ARPES Spectra of Bi2212 give the Coulomb Coupling $λ^{C}\approx 1$ and the Electron-Phonon Coupling $λ^{EP}=2-3$
We show that the double kink-structure in the electronic self-energy of Bi2212 near the nodal point at low energy $\omega_{1}\approx 50-70$ $meV$ and at high energy at $\omega_{2}\approx 350$ $meV$, observed recently in the ARPES measurements by Valla et al \cite{Valla-2006}, gives that the electron-phonon (EPI) coupli...
0610549v2
2006-10-23
Strong vs. Weak Coupling Duality and Coupling Dependence of the Kondo Temperature in the Two-Channel Kondo Model
We perform numerical renormalization group (NRG) as well as analytical calculations for the two-channel Kondo model to obtain the dependence of the Kondo temperature $T_K$ on the dimensionless (bare) spin exchange coupling $g$ over the complete parameter range from $g\ll 1$ to $g\gg 1$. We show that there exists a dual...
0610631v2
2007-03-11
Strong electron-phonon coupling in the rare-earth carbide superconductor La2C3
We present the results of a crystal structure determination using neutron powder diffraction as well as the superconducting properties of the rare-earth sesquicarbide La2C3 (Tc ~ 13.4 K) by means of specific heat and upper critical field measurements. From the detailed analysis of the specific heat and a comparison wit...
0703279v1
2007-03-23
Dissipative Landau-Zener transitions of a qubit: bath-specific and universal behavior
We study Landau-Zener transitions in a qubit coupled to a bath at zero temperature. A general formula is derived that is applicable to models with a non-degenerate ground state. We calculate exact transition probabilities for a qubit coupled to either a bosonic or a spin bath. The nature of the baths and the qubit-bath...
0703596v2
2006-12-07
Decentralized Maximum Likelihood Estimation for Sensor Networks Composed of Nonlinearly Coupled Dynamical Systems
In this paper we propose a decentralized sensor network scheme capable to reach a globally optimum maximum likelihood (ML) estimate through self-synchronization of nonlinearly coupled dynamical systems. Each node of the network is composed of a sensor and a first-order dynamical system initialized with the local measur...
0612042v1
2005-11-16
Non-Abelian Einstein-Born-Infeld-Dilaton Cosmology
The non-abelian Einstein-Born-Infeld-Dilaton theory, which rules the dynamics of tensor-scalar gravitation coupled to a $su(2)$-valued gauge field ruled by Born-Infeld lagrangian, is studied in a cosmological framework. The microscopic energy exchange between the gauge field and the dilaton which results from a non-uni...
0511090v2
2005-11-30
Coupling of spacetime atoms and spin foam renormalisation from group field theory
We study the issue of coupling among 4-simplices in the context of spin foam models obtained from a group field theory formalism. We construct a generalisation of the Barrett-Crane model in which an additional coupling between the normals to tetrahedra, as defined in different 4-simplices that share them, is present. T...
0512002v1
2006-02-24
Dynamics of Scalar Field in Polymer-like Representation
In recent twenty years, loop quantum gravity, a background independent approach to unify general relativity and quantum mechanics, has been widely investigated. We consider the quantum dynamics of a real massless scalar field coupled to gravity in this framework. A Hamiltonian operator for the scalar field can be well ...
0602101v1
2006-06-19
Loop cosmological implications of a non-minimally coupled scalar field
Non-minimal actions with matter represented by a scalar field coupled to gravity are considered in the context of a homogeneous and isotropic universe. The coupling is of the form $-\xi/2 \phi^2 R$. The possibility of successful inflation is investigated taking into account features of loop cosmology. For that end a co...
0606082v1
2005-12-15
Search for Anomalous Couplings in Top Decay at Hadron Colliders
We present a quantitative study on sensitivities to the top-decay anomalous couplings, taking into account realistic experimental conditions expected at Tevatron and LHC. A double angular distribution of W and charged lepton in the top decay is analyzed, using ttbar events in the lepton+jets channel. In order to improv...
0512037v1
1992-10-19
Fermion-Higgs model with strong Wilson-Yukawa coupling in two dimensions
The fermion mass spectrum is studied in the quenched approximation in the strong coupling vortex phase (VXS) of a globally U(1)$_L \otimes$U(1)$_R$ symmetric scalar-fermion model in two dimensions. In this phase fermion doublers can be completely removed from the physical spectrum by means of a strong Wilson-Yukawa cou...
9210022v1
1994-06-02
Radiative Corrections to the Kinetic Couplings in Nonrelativistic Lattice QCD
The heavy-quark mass and wave function renormalizations, energy shift, and radiative corrections to two important couplings, the so-called kinetic couplings, in nonrelativistic lattice QCD are determined to leading order in tadpole-improved perturbation theory. The scales at which to evaluate the running QCD coupling f...
9406002v1
1994-12-04
How to Accurately Extract the Running Coupling of QCD from Lattice Potential Data
By (a) using an expression for the LATTICE potential of QCD in terms of a CONTINUUM running coupling and (b) globally parameterizing this coupling to interpolate between 2- (or higher-) loop QCD in the UV and the flux tube prediction in the IR, we can perfectly fit lattice data for the potential down to ONE lattice spa...
9412022v1
1995-06-01
Four-point renormalized coupling constant in O(N) models
The renormalized zero-momentum four-point coupling $g_r$ of O(N)-invariant scalar field theories in $d$ dimensions is studied by applying the 1/N expansion and strong coupling analysis. The O(1/N) correction to the $\beta$-function and to the fixed point value $g_r^*$ are explictly computed. Strong coupling series for ...
9506002v1
1995-09-05
Four-point renormalized coupling constant in O(N) models
The renormalized zero-momentum four-point coupling $g_r$ of $O(N)$-invariant scalar field theories in $d$ dimensions is studied by applying the $1/N$ expansion and strong coupling analysis. The $O(1/N)$ correction to the $\beta$-function and to the fixed point value $g_r^*$ are explictly computed. Strong coupling serie...
9509005v1
1997-09-30
The Schrödinger functional running coupling with staggered fermions and its application to many flavor QCD
We discuss the Schr\"odinger functional in lattice QCD with staggered fermions and relate it, in the classical continuum limit, to the Schr\"odinger functional regularized with Wilson fermions. We compute the strong coupling constant defined via the Schr\"odinger functional with staggered fermions at one loop and show ...
9709159v1