Level spacing statistics of disordered finite superlattices spectra and motional narrowing as a random matrix theory effect
نویسندگان
چکیده
In the present work the problem of coupled disordered quantum wells is addressed in a random matrix theory framework. The quantum wells are short repulsive binary alloys embeded by ordered barriers and show well defined quantized levels as a consequence of spatial confinement. Finite disordered superlattices may show both diffusive-like and localized minibands. Three different level repulsion suppression mechanisms are discussed by analysing the evolution of nearest-level-spacing distribution function within each superlattice miniband. The present numerical results show a motional narrowing effect, which is in fact a consequence of the random matrix theory. PACS number(s) 71.23.An,73.20.Jc,74.40.+k,73.20.Dx
منابع مشابه
Scaling of Level Statistics at the Metal–insulator Transition
Using the Anderson model for disordered systems the fluctuations in electron spectra near the metal–insulator transition were numerically calculated for lattices of sizes up to 28 × 28 × 28 sites. The results show a finite–size scaling of both the level spacing distribution and the variance of number of states in a given energy interval, that allows to locate the critical point and to determine...
متن کاملCritical level statistics at the Anderson transition in four - dimensional disordered systems
The level spacing distribution is numerically calculated at the disorder-induced metal–insulator transition for dimensionality d = 4 by applying the Lanczos diagonalisation. The critical level statistics are shown to deviate stronger from the result of the random matrix theory compared to those of d = 3 and to become closer to the Poisson limit of uncorrelated spectra. Using the finite size sca...
متن کاملCritical level spacing distribution of two - dimensional disordered systems with spin - orbit coupling
The energy level statistics of 2D electrons with spin-orbit scattering are considered near the disorder induced metal-insulator transition. Using the Ando model, the nearest-level-spacing distribution is calculated numerically at the critical point. It is shown that the critical spacing distribution is size independent and has a Poisson-like decay at large spacings as distinct from the Gaussian...
متن کاملElectronic Transmission Wave Function of Disordered Graphene by Direct Method and Green's Function Method
We describe how to obtain electronic transport properties of disordered graphene, including the tight binding model and nearest neighbor hopping. We present a new method for computing, electronic transport wave function and Greens function of the disordered Graphene. In this method, based on the small rectangular approximation, break up the potential barriers in to small parts. Then using the f...
متن کاملMicroscopic theory of motional narrowing of microcavitypolaritons in a disordered
The innuence of static disorder on the optical properties of microcavity-embedded quantum wells is studied by means of a microscopic model. Both the exciton-photon coupling and the exciton-disorder interaction are treated non-perturbatively. Despite the nonconservation of the in-plane momentum due to disorder, the Rabi splitting is still present. Moreover, the lower polari-ton is subject to mot...
متن کامل