Dependences of the Transport Scattering Time and Quantum Lifetime on the Two-Dimensional Electron Gas Density in Modulation-Doped Single GaAs Quantum Wells with AlAs/GaAs Short-Period Superlattice Barriers
| Autor: | I. S. Strygin, A. K. Bakarov, D. V. Nomokonov, A. V. Goran, A. A. Bykov |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Physics
Physics and Astronomy (miscellaneous) Condensed Matter - Mesoscale and Nanoscale Physics Scattering Superlattice Doping FOS: Physical sciences Electron Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Ionization Mesoscale and Nanoscale Physics (cond-mat.mes-hall) mental disorders Atomic physics Fermi gas Electron scattering Quantum well |
| Popis: | The dependences of the transport scattering time {\tau}t, quantum lifetime {\tau}q, and their ratio {\tau}t/{\tau}q on the density ne of the electron gas in modulation-doped single GaAs quantum wells with AlAs/GaAs short-period super-lattice barriers are investigated. The experimental dependences are explained in terms of electron scattering by remote ionized donors with an effective two-dimensional concentration n*R and background impurities with a three-dimensional concentration nB. An expression for n*R(ne) is obtained including the contribution of X-valley electrons localized in AlAs layers to the suppression of scattering by the random potential of remote donors. It is shown that the experimentally observed abrupt increase in {\tau}t and {\tau}q with an increase in ne above a certain critical value nec is related to a decrease in n*R. It is established that the drop in {\tau}t/{\tau}q observed for electron densities ne > nec occurs because scattering by the random potential of background impurities in this two-dimensional system with a decrease in n*R limits an increase in {\tau}t more considerably than an increase in {\tau}q. Comment: 9 pages, 5 figures |
| Databáze: | OpenAIRE |
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