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Study of Spin-Dependent Tunneling Through Nonmagnetic Semiconductor Multi-Layer Stucture

Author: WangRuiQin
Tutor: GongJian
School: Inner Mongolia University
Course: Physics
Keywords: Non - magnetic semiconductors Dresselhaus spin -orbit coupling Resonant tunneling spin polarization Tunneling Lifetime
CLC: O471
Type: Master's thesis
Year: 2011
Downloads: 15
Quote: 0
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Abstract


The effective mass approximation , the non-magnetic semiconductor materials GaSb grown multilayer structure as the object of study , included in the k3Dresselhaus spin-orbit coupling effects , study issues related to the spin-polarized resonant tunneling : the transmission coefficient tunnel to wear life polarizability First , research symmetrical double-barrier structure Al-xGa1-xSb (x = 0.15/0.3/0/0.3/0.15) the dynamics of electron spin polarized transport . consider k3Dresselhaus spin-orbit coupling effects , combined with the transfer matrix and the Runge-Kutta method to solve the time-dependent Schr?dinger equation , and then discuss the transmission coefficient of the electronic structure , tunneling lifetime and polarization rate . findings included in k3Dresselhaus spin-orbit coupling term , the different spin states of electrons resonance transmission peak splitting of spin- up and spin - down electrons , respectively, in each of the resonance energy at the resonance peak the electronic to these resonances level for the incident energy appears when 100% polarization ; spin- up and spin - down electrons build time and escape time , which may be caused by the spin polarization of resonance energy levels of electrons in different spin states experienced a certain period of time when the next incident , have reached a stable completely polarized . addition , symmetric multi- barrier structure GaSb/Alo.3Gao.7Sb number N of the barrier transmission coefficient , and Dresselhaus since electronic spin- orbit coupled spin-polarized tunneling study shows that splitting occurs due to the periodic structure in the coupling between the wells , the electron resonance level . corresponds to the potential barrier of the number N , will be split into the N-1 formant . included the effect of the Dresselhaus spin -orbit coupling , the transmission curves obvious spin splitting , spin down electrons corresponding formant move to the low-energy region , spin up electrons corresponding formant to mobile high energy region and both splitting with the increase in the number of barrier there , splitting the principles of non - spin-polarized case spin oscillations with the change of the incident energy , the electron spin polarization this oscillation , and with the increase of the number of cycles , more intense , and at the same time completely spin polarized resonance energy state .

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CLC: > Mathematical sciences and chemical > Physics > Semiconductor physics > Semiconductive Theory
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