Related papers: Instanton tunneling and multiphonon giant resonanc…
Some aspects of the connection between differential geometry and multidimensional soliton equations are discussed.
The sine-Gordon model captures the low-energy effective dynamics of a wealth of one-dimensional quantum systems, stimulating the experimental efforts in building a versatile quantum simulator of this field theory and fueling the parallel…
In a recent Letter [1] an overall agreement with the experimental data for the excitation of the single and double giant dipole resonances in relativistic heavy ion collision in 136Xe and 208Pb nuclei has been reported. We point out that…
Non-perturbative effects of instanton-like solutions are studied within the framework of supergravity theories with field-dependent gauge functions. Fermionic zero modes are constructed and some typical correlation functions are evaluated.…
We study the sine-Gordon quantum field theory at finite temperature by generalizing the method of random surfaces to compute the free energy and one-point functions of exponential operators non-perturbatively. Focusing on the gapped phase…
The role of anharmonic effects on the excitation of the double giant dipole resonance is investigated in a simple macroscopic model.Perturbation theory is used to find energies and wave functions of the anharmonic ascillator.The cross…
We study by Monte Carlo techniques the evolution of finite two-dimensional Ising systems in oscillating magnetic fields. The phenomenon of stochastic resonance is observed. The characteristic peak obtained for the correlation function…
A number of observables are constructed which can give useful information on instanton ensembles.The basic properties used are : (1) Instantons are SU(2) configurations ,(2)They are self-dual or antiself-dual.
We apply the idea of giant slow wave resonance associated with a degenerate photonic band edge to gain enhancement of active media. This approach allows to dramatically reduce the size of slow wave resonator while improving its performance…
At large distances and in the low temperature phase, the quenched correlation functions in the 2d random phase sine-Gordon model have been argued to be of the form~: $ \bar {\vev{~[\varphi(x)-\varphi(0)]^2~}}_* = A (\log|x|) + B \ep^2…
The sine-Gordon model is discussed and analyzed within the framework of the renormalization group theory. A perturbative renormalization group procedure is carried out through a decomposition of the sine-Gordon field in slow and fast modes.…
A numerical approach is proposed for studying the quantum optical modes in the Klein-Gordon lattices where the energy contribution of the atomic displacements is non-quadratic. The features of the biphonon excitations are investigated in…
The shape fluctuations due to thermal effects in the giant dipole resonance (GDR) observables are calculated using the exact free energies evaluated at fixed spin and temperature. The results obtained are compared with Landau theory…
We evaluate the two pion decay of the Roper resonance in a model where explicit re-scattering of the two final pions is accounted for by the use of unitarized chiral perturbation theory. Our model does not include an explicit $\epsilon$ or…
Numerical and anaytical studies of the instanton liquid model have allowed the determination of many hadronic parameters during the last 13 years. Most part of this thesis is devoted to the extension of the analytical methods. The meson…
Machine learning methods are applied to finding the Green's function of the Anderson impurity model, a basic model system of quantum many-body condensed-matter physics. Different methods of parametrizing the Green's function are…
This work provides the community with an easily executable open-source Python package designed to automize the evaluation of Interfacial Phonons (InterPhon). Its strategy of arbitrarily defining the interfacial region and periodicity…
The Sine-Gordon equation in (1+2) dimensions has N-soliton solutions that propagate at velocities that are lower than the speed of light (c = 1), for any N greater tha or equal to 1. A first integral of the equation, which vanishes…
The effect of deformation on the excitation of multiple giant dipole resonances is studied. Analytical expressions are derived in the framework of the interacting boson model for the energies and E1 properties of giant dipole resonances in…
Phonon-assisted tunneling rates are evaluated for a well isolated double dot system defined in a GaAs semiconductor heterostructure of finite thickness. A separable model for the confining potential allows accurate determinations of doublet…