Influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors

The doping of semiconductors with magnetic impurities gives rise not only to a spin-spin interaction between quasifree carriers and magnetic impurities but also to a local spin-independent disorder potential for the carriers. Based on a quantum kinetic theory for the carrier and impurity density mat...

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Autor principal: Tamborenea, Pablo Ignacio
Publicado: 2017
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_24699950_v95_n4_p_Cygorek
http://hdl.handle.net/20.500.12110/paper_24699950_v95_n4_p_Cygorek
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling paper:paper_24699950_v95_n4_p_Cygorek2023-06-08T16:36:14Z Influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors Tamborenea, Pablo Ignacio The doping of semiconductors with magnetic impurities gives rise not only to a spin-spin interaction between quasifree carriers and magnetic impurities but also to a local spin-independent disorder potential for the carriers. Based on a quantum kinetic theory for the carrier and impurity density matrices as well as the magnetic and nonmagnetic carrier-impurity correlations, the influence of the nonmagnetic scattering potential on the spin dynamics in DMS after optical excitation with circularly polarized light is investigated using the example of Mn-doped CdTe. It is shown that non-Markovian effects, which are predicted in calculations where only the magnetic carrier-impurity interaction is accounted for, can be strongly suppressed in the presence of nonmagnetic impurity scattering. This effect can be traced back to a significant redistribution of carriers in k-space which is enabled by the build-up of large carrier-impurity correlation energies. A comparison with the Markov limit of the quantum kinetic theory shows that, in the presence of an external magnetic field parallel to the initial carrier polarization, the asymptotic value of the spin polarization at long times is significantly different in the quantum kinetic and the Markovian calculations. This effect can also be attributed to the formation of strong correlations, which invalidates the semiclassical Markovian picture and it is stronger when the nonmagnetic carrier-impurity interaction is accounted for. In an external magnetic field perpendicular to the initial carrier spin, the correlations are also responsible for a renormalization of the carrier spin precession frequency. Considering only the magnetic carrier-impurity interaction, a significant renormalization is predicted for a very limited set of material parameters and excitation conditions. Accounting also for the nonmagnetic interaction, a relevant renormalization of the precession frequency is found to be more ubiquitous. © 2017 American Physical Society. Fil:Tamborenea, P.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2017 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_24699950_v95_n4_p_Cygorek http://hdl.handle.net/20.500.12110/paper_24699950_v95_n4_p_Cygorek
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description The doping of semiconductors with magnetic impurities gives rise not only to a spin-spin interaction between quasifree carriers and magnetic impurities but also to a local spin-independent disorder potential for the carriers. Based on a quantum kinetic theory for the carrier and impurity density matrices as well as the magnetic and nonmagnetic carrier-impurity correlations, the influence of the nonmagnetic scattering potential on the spin dynamics in DMS after optical excitation with circularly polarized light is investigated using the example of Mn-doped CdTe. It is shown that non-Markovian effects, which are predicted in calculations where only the magnetic carrier-impurity interaction is accounted for, can be strongly suppressed in the presence of nonmagnetic impurity scattering. This effect can be traced back to a significant redistribution of carriers in k-space which is enabled by the build-up of large carrier-impurity correlation energies. A comparison with the Markov limit of the quantum kinetic theory shows that, in the presence of an external magnetic field parallel to the initial carrier polarization, the asymptotic value of the spin polarization at long times is significantly different in the quantum kinetic and the Markovian calculations. This effect can also be attributed to the formation of strong correlations, which invalidates the semiclassical Markovian picture and it is stronger when the nonmagnetic carrier-impurity interaction is accounted for. In an external magnetic field perpendicular to the initial carrier spin, the correlations are also responsible for a renormalization of the carrier spin precession frequency. Considering only the magnetic carrier-impurity interaction, a significant renormalization is predicted for a very limited set of material parameters and excitation conditions. Accounting also for the nonmagnetic interaction, a relevant renormalization of the precession frequency is found to be more ubiquitous. © 2017 American Physical Society.
author Tamborenea, Pablo Ignacio
spellingShingle Tamborenea, Pablo Ignacio
Influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors
author_facet Tamborenea, Pablo Ignacio
author_sort Tamborenea, Pablo Ignacio
title Influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors
title_short Influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors
title_full Influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors
title_fullStr Influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors
title_full_unstemmed Influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors
title_sort influence of nonmagnetic impurity scattering on spin dynamics in diluted magnetic semiconductors
publishDate 2017
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_24699950_v95_n4_p_Cygorek
http://hdl.handle.net/20.500.12110/paper_24699950_v95_n4_p_Cygorek
work_keys_str_mv AT tamboreneapabloignacio influenceofnonmagneticimpurityscatteringonspindynamicsindilutedmagneticsemiconductors
_version_ 1768542525638836224

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