Resonant light scattering by a gradient quantum well

Resonant scattering of monochromatic light by a quantum well with the frequency of its excitonic resonance varying along a certain direction in the plane of the well is studied experimentally and theoretically. It is shown that the simplest model of a thin inhomogeneous layer that yields an exact solution of the direct and inverse scattering problems allows one to successfully describe the experimental observation of resonant scattering by a GaAs/AlGaAs quantum well with the frequency of the exciton resonance linearly varying in the plane of the well.     

Electronic resonances in a quantum well having a periodically uneven boundary

The spectrum of the electronic states in an infinitely deep two-dimensional potential well, where one wall is periodically uneven, is investigated theoretically. It is shown that in non-Bragg type resonances — standing electron wave resonances, which are modes of different spatial harmonics of the electron wave function — arise in such a well. The resonances occur in a wide range of energies, starting at values close to the bottom in each 2D subband. The resonance interaction splits the energy spectrum and results in the appearance of gaps, giving the electron spectrum a miniband character. The properties of the electron gas vary substantially in accordance with the new characteristics of the spectrum. Fiz. Tverd. Tela (St. Petersburg) 41, 1867–1870 (October 1999)     

Resonance scattering in quantum wells with nanocenters

It is shown that, in 2D electron layers, nanocenters of finite radius (quantum dots, donors) may give rise to Fano resonances in the scattering cross section. The resonance contribution to the residual resistance is calculated.     

Intrasubband light absorption in a parabolic quantum well with consideration of scattering on the three-dimensional optical phonons

Within the frameworks of the second order perturbation theory the light absorption by free carriers in a parabolic quantum well (QW) is investigated taking into account the scattering by the three-dimensional optical phonons. An analytical expression for the absorption coefficient is obtained taking into the consideration two processes, with initial absorption of a photon and further scattering by optical phonons, and with the initial scattering by the optical phonons and the subsequent absorption of the photon. Frequency characteristics and dependences on the temperature and the width of QW are examined.     

Resonant elastic scattering of light from single quantum wells in semiconductor multilayers

A theory is developed for steady-state elastic scattering of light via quasi-2D excitons from a quantum well (QW) whose interfaces are randomly rough. The study is mainly focused on the angle dependences of radiation giving direct information about static disorder responsible for the elastic scattering. A nonlocal excitonic susceptibility is expressed in terms of random profile functions of QW interfaces. Treated is elastic scattering of light from a disordered QW in the following actual dielectric environments: (i) a uniform background, (ii) a Fabry–Perot film with rough boundaries, and (iii) a semiconductor microcavity. The cross-sections are derived analytically for scattering of linearly polarized light to the lowest (Born's) approximation with arbitrary roughness statistics. The spectral and angle dependencies of scattering intensity are analyzed numerically in the absolute-value scale with Gaussian correlation of interface roughness. The probability 10⁻² was found for the exciton-mediated scattering of a photon from a QW interface roughness whose root-mean-square height is on the level of 2×10⁻¹ nm. This probability is shown to exceed by two orders of magnitude that is typical of resonant scattering from either a single semiconductor surface or rough boundaries of a semiconductor Fabry–Perot film containing the QW. The scattering spectrum of a QW placed in a microcavity is predicted to have a doublet structure whose components are associated with the cavity exciton–polaritons.     

Resonance scattering of sound by spheroidal elastic bodies and shells

The resonances of spheroidal elastic bodies (prolate and oblate) in the form of solid bodies and shells are determined using dynamic elasticity theory and Debye potentials. In addition to analytic solutions, results of computer calculations are presented for the angular characteristics and scattering cross sections of spheroidal elastic bodies.     

Resonance theory of elastic wave scattering from a cylindrical cavity

Resonant excitation of a fluid-filled cylindrical cavity in an elastic medium by an incident compressional wave is investigated on the basis of the resonance theory of nuclear scattering. It is shown that the scattering amplitude consists of a series of narrow resonances super-imposed upon, and interfering with, a broad background that corresponds to the scattering from an empty cavity. The resonances may be analyzed in a most enlightening fashion by studying them separately in each partial wave of the normal-mode series. They are seen to correspond to excitations of the eigenvibrations of the cavity fluid caused by a phase-match of “creeping waves”, similar to the “Regge poles” of nuclear physics.     

Slow light propagation via quantum coherence in a semiconductor quantum well

With the Schrödinger equations, we investigate the low-intensity light pulse propagation through a semiconductor quantum wells. Through studying the dispersion and absorption properties of the weak probe field, it is shown that slow light propagation is observed in this system. From the view point of practical purpose, it is more advantageous than its corresponding atomic system. Such investigation of slow light propagation may lead to important practical applications in semiconductor quantum information.     

Inelastic light scattering by acoustic phonons in quantum dots and quantum films

The Raman scattering spectra were analyzed in order to find and explain similarities and differences in the interaction between electrons and acoustic phonons in quantum dots and quantum films.