Anisotropy of quantum interference in disorderedGaAs/Alx

Abstract

The influence of the anisotropic disorder on quantum interference was studied in the intentionally disordered GaAs/Al x Ga 1Ϫx As superlattices. In the case of sufficiently strong disorder the quantum interference exhibited a structural dependence resulting in the anisotropy of the phase-breaking time, which was found shorter in the direction of the disorder. The anisotropy effects were shown stronger in the insulating transport regime than in the metallic one. The weak-localization negative magnetoresistance was used to obtain the vertical coupling constant in the disordered superlattices.

Anisotropic three-dimensional weak localization in ultrananocrystalline diamond films with nitrogen inclusions

“…The PFS model was originally developed to explain transport in disordered artificial superlattices. In contrast, an anisotropic 3DWL approach in the diffusive Fermi surface (DFS) limit was recently used to explain the transport in nanocrystalline silicon films 60 to account for an artificially formed SL structure 61,62 . This approach 63 yields the following basic expression for the conductivity (resistance) correction:…”

Resonant Rayleigh scattering in ordered and disordered semiconductor superlattices

“…As an example, magnetotransport measurements in doped semiconductor superlattices recently allowed the study of the effects of the anisotropy on the phase-breaking time of the electrons. 2 In the present work, we measure simultaneously the continuous wave resonant Rayleigh scattering ͑RRS͒, the photoluminescence ͑PL͒, and photoluminescence excitation ͑PLE͒ spectra of semiconductor SL's in a magnetic field to study the influence of the vertically correlated and uncorrelated anisotropic disorders on the coherence relaxation and exciton localization. We use this technique since RRS has access to information on the effective localization and on the spectral dispersion of the dephasing, 4 while the PL and PLE spectra in magnetic field are valid techniques to study the exciton delocalization along z.…”

“…In recent years, a large number of studies has been devoted to explore the general properties of disordered systems through the investigation of the optical response and transport properties of semiconductor nanostructures. An important topic in the physics of disordered systems is to understand the influence of an intentionally disordered potential profile along the growth axis z in semiconductor superlattices (SL's) on quantum interference and carrier localization [1,2,3]. SL's are excellent candidates to perform such a study since the advances achieved in molecular beam epitaxy (MBE) allow the fabrication SL's tailored with desired conduction-and valence-band profiles.…”

“…The global result is an anisotropic disorder which effect on the quantum interference has become an interesting subject of recent experimental studies. As an example, magneto-transport measurements in doped semiconductor superlattices recently allowed the study of the effects of the anisotropy on the phase-breaking time of the electrons [2].…”