ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Exciton states in type-II InP/InGaP and GaSb/GaAs self-assembled quantum dots andquantum-dot superlattices subject to a normal magnetic field are calculated. Strain is explicitlytaken into account in single particle models of the electronic structure, while an exactdiagonalization approach is adopted to compute the exciton states. Strain reverts type II bandalignment in InP quantum dots to type I, therefore no transitions between the lowest energy states ofdifferent angular momenta are observed. On the other hand, strain increases the barrier for theelectron in the conduction band of GaSb/GaAs quantum dots, therefore the exciton, beingcomposed of electron and hole states of various angular momenta, may have a finite angularmomentum in the ground state. Consequently, the oscillator strength in the InP single quantum dotand quantum-dot superlattice increases with the magnetic field, while the angular momentumtransitions between the bright and the dark exciton states in the GaSb system bring about decay ofthe oscillator strength when the magnetic field exceeds a certain value
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.518.51.pdf
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