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showing 10 items of 2571 documents
Renormalization group flows for Wilson-Hubbard matter and the topological Hamiltonian
2019
Understanding the robustness of topological phases of matter in the presence of interactions poses a difficult challenge in modern condensed matter, showing interesting connections to high energy physics. In this work, we leverage these connections to present a complete analysis of the continuum long-wavelength description of a generic class of correlated topological insulators: Wilson-Hubbard topological matter. We show that a Wilsonian renormalization group (RG) approach, combined with the so-called topological Hamiltonian, provide a quantitative route to understand interaction-induced topological phase transitions that occur in Wilson-Hubbard matter. We benchmark two-loop RG predictions …
Mapping acoustical activity in 3D chiral mechanical metamaterials onto micropolar continuum elasticity
2020
Abstract We compare the phonon band structures and chiral phonon eigenmodes of a recently experimentally realized three-dimensional (3D) cubic chiral metamaterial architecture to results from linear micropolar elasticity, an established generalization of classical linear Cauchy elasticity. We achieve very good qualitative agreement concerning the anisotropies of the eigenfrequencies, the anisotropies of the eigenmode properties of the acoustic branches, as well as with respect to the observed pronounced sample-size dependence of acoustical activity and of the static push-to-twist conversion effects. The size dependence of certain properties, that is, the loss of scale invariance, is a finge…
Renormalization of the Fröhlich constant for electrons in a quantum dot
2002
Recent experimental investigations of far-infrared attenuation in GaAs/InAs quantum dot in magnetic field and measurements of photoluminescence features for smaller pyramid-shape GaAs/InAs quantum dots indicated an enhancement of coupling of longitudinal optical phonons with confined electrons, which manifested itself in a significant increase of the effective Frohlich constant in comparison to its bulk value. We give a simple quasiclassical explanation of this enhancement and relate the renormalization of the Frohlich constant with the dot diameter.
Unguided plasmon-mode resonance in optically excited thin film: exact modal description of Kretschmann–Raether experiment
2013
With the aim of studying electromagnetic surface wave resonance, we rigorously solve the homogeneous and inhomogeneous problem associated with an optically excited thin metallic film. We then demonstrate unambiguously that the excited eigenmode engendering plasmonic resonance in the so-called Kretschmann–Raether configuration is an unguided mode (i.e., with an anti-evanescent structure). This result, challenging the classical interpretation of the outgoing wave condition applied to surface waves, permits a quantitative interpretation of the attenuated total reflection curves.
Non-Perturbative Renormalization of Lattice Four-Fermion Operators without Power Subtractions
1999
A general non-perturbative analysis of the renormalization properties of $\Delta I=3/2$ four-fermion operators in the framework of lattice regularization with Wilson fermions is presented. We discuss the non-perturbative determination of the operator renormalization constants in the lattice Regularization Independent (RI or MOM) scheme. We also discuss the determination of the finite lattice subtraction coefficients from Ward Identities. We prove that, at large external virtualities, the determination of the lattice mixing coefficients, obtained using the RI renormalization scheme, is equivalent to that based on Ward Identities, in the continuum and chiral limits. As a feasibility study of …
The η transition form factor from space- and time-like experimental data
2015
The $\eta$ transition form factor is analysed for the first time in both space- and time-like regions at low and intermediate energies in a model-independent approach through the use of rational approximants. The $\eta\rightarrow e^+e^-\gamma$ experimental data provided by the A2 Collaboration in the very low energy region of the dilelectron invariant mass distribution allows for the extraction of the most precise up-to-date slope and curvature parameters of the form factors as well as their values at zero and infinity. The impact of these new results on the mixing parameters of the $\eta$-$\eta^\prime$ system, together with the role played by renormalisation dependent effects, and on the d…
Gravitational Waves from Rotating Proto-Neutron Stars
2004
We study the effects of rotation on the quasi normal modes (QNMs) of a newly born proto neutron star (PNS) at different evolutionary stages, until it becomes a cold neutron star (NS). We use the Cowling approximation, neglecting spacetime perturbations, and consider different models of evolving PNS. The frequencies of the modes of a PNS are considerably lower than those of a cold NS, and are further lowered by rotation; consequently, if QNMs were excited in a sufficiently energetic process, they would radiate waves that could be more easily detectable by resonant-mass and interferometric detectors than those emitted by a cold NS. We find that for high rotation rates, some of the g-modes bec…
Temporal and spatial persistence of combustion fronts in paper
2003
The spatial and temporal persistence, or first-return distributions are measured for slow-combustion fronts in paper. The stationary temporal and (perhaps less convincingly) spatial persistence exponents agree with the predictions based on the front dynamics, which asymptotically belongs to the Kardar-Parisi-Zhang universality class. The stationary short-range and the transient behavior of the fronts are non-Markovian, and the observed persistence properties thus do not agree with the predictions based on Markovian theory. This deviation is a consequence of additional time and length scales, related to the crossovers to the asymptotic coarse-grained behavior. Peer reviewed
Intra- and Interchain Correlations in Semidilute Polymer Solutions: Monte Carlo Simulations and Renormalization Group Results
2000
We investigate the intra- and intermolecular correlations in semidilute polymer solutions by large-scale computer simulations and renormalization group calculations. In the framework of the bond fluctuation model we study polymers with chain lengths up to N = 2048 monomers and determine the intermolecular pair correlation function, the coherent scattering intensity, and its distinct part at all length scales. The simulations are compared quantitatively to renormalization group calculations of the universal crossover scaling function. Special attention is paid to length scales smaller than the density screening length ξ, where the distinct part of the scattering function in the simulations i…
Phase Equilibria of Lattice Polymers from Histogram Reweighting Monte Carlo Simulations
1998
Histogram-reweighting Monte Carlo simulations were used to obtain polymer / solvent phase diagrams for lattice homopolymers of chain lengths up to r=1000 monomers. The simulation technique was based on performing a series of grand canonical Monte Carlo calculations for a small number of state points and combining the results to obtain the phase behavior of a system over a range of temperatures and densities. Critical parameters were determined from mixed-field finite-size scaling concepts by matching the order parameter distribution near the critical point to the distribution for the three-dimensional Ising universality class. Calculations for the simple cubic lattice (coordination number z…