The interaction between localized and extended vibrational modes in solids is of central importance in understanding how local vibrational modes (LVMs) decay into phonons. In this study, we have investigated interstitial oxygen (Oi) in silicon as a model ‘laboratory’ for such local-extended mode interactions. Using hydrostatic pressure and infrared spectroscopy, we brought the stretch mode of O...

in the present paper, resonant frequencies and modes of a three-atom photonic molecule and a photonic crystal placed within a cavity are numerically calculated. first, governing formulation in transverse electric field mode (te) is obtained using maxwell equations. then, an algorithm based on a finite difference scheme and matrix algebra is presented. the algorithm is then implemented in a comp...

I compare heatkernel regularization with sharp gauge invariant cutoffs in the Hamiltonian formulation of the Coulomb gauged Schwinger model on a circle. The effective potential for the zero mode of the gauge field in a given fermionic configuration is different in these two regularizations, the difference being independent of the chosen fermionic configuration. In the continuum limit L → ∞ the ...

We compare the behavior of different lattice Dirac operators in gauge backgrounds which are lattice discretizations of a classical instanton. In particular we analyze the overlap Dirac operator, a chirally improved Dirac operator and the standard Wilson operator. We discuss the flow of real eigenvalues as a function of the instanton size. An analysis of the eigenvectors shows that, due to their...

Dynamical topological solitons are studied in classical two–dimensional Heisenberg easy–axis ferromagnets. The properties of such solitons are treated both analytically in the continuum limit and numerically by spin dynamics simulations of the discrete system. Excitation of internal mode causes orbital motion. This is confirmed by simulations. Submitted to: J. Phys.: Condens. Matter PACS number...

For the problem of estimating a sparse sequence of coefficients of a parametric or nonparametric generalized linear model, posterior mode estimation with a Subbotin(λ, ν) prior achieves thresholding and therefore model selection when ν ∈ [0, 1] for a class of likelihood functions. The proposed estimator also offers a continuum between the (forward/backward) best subset estimator (ν = 0), its ap...

An anisotropic photonic crystal containing two defect layers is considered. It demonstrated that the system can support a Fabry-Perot bound state in continuum (FP-BIC). A fully analytic solution of scattering problem as well condition for FP-BIC have been derived framework temporal coupled-mode theory.

We examine the quantum structure of continuum entanglement and in the context of short-pulse down-conversion we answer the open question of how many of the uncountably many frequency modes contribute effectively to the entanglement. We derive a set of two-photon mode functions that provide an exact, discrete, and effectively finite basis for characterizing pairwise entanglement. Our analysis pr...

We analyze the dynamics of an SUL(2)⊗UR(1) chiral theory on the lattice with a strong multifermion coupling. It is shown that no spontaneous symmetry breaking occurs; the “spectator” fermion ψR is a free mode; doublers are decoupled as massive Dirac fermions consistently with the chiral symmetries. In 1+1 dimension, we show that the right-handed three-fermion state disappears at the threshold a...

We have simultaneously excited a coherent and a squeezed phonon field in SrTiO3 using femtosecond laser pulses and stimulated Raman scattering. The frequency of the coherent state (a 1.3 THz) is that of the A1g-component of the soft mode responsible for the cubic-tetragonal phase transformation at approximately 110 K. The squeezed field involves a continuum of transverse acoustic phonons domina...