Dissertation > Mathematical sciences and chemical > Physics > Semiconductor physics > Semiconductive Theory

Impurity states and their quantum tunneling quantum ring

Author WangBoZuo
Tutor KongXiaoJun
School Hebei Normal
Course Condensed Matter Physics
Keywords Quantum ring Impurity states Binding energy Resonant tunneling
CLC O471
Type Master's thesis
Year 2007
Downloads 54
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Team in 1997 A.Lorke growth for the first time quantum ring structure , its unique physical properties make it quickly became one of the hot research field of condensed matter physics . In theoretical and experimental research on the physical properties of the quantum ring have been widely spread . As the thickness of the quantum ring is small enough , the two-dimensional square potential well model can describe the electronic states of the quantum ring . We selected two-dimensional infinite cylindrical square barrier model to study the quantum ring the impurity state level and the probability distribution law , we also study the problem of impurities in the AB center of the ring when tunneling . First , we use the method of separation of variables and diagonalization method to study the impurities of impurities in the center of the ring , the typical quantum ring (r 1 = 10nm, r 2 = 50nm) state energy and the binding energy of the nature of the analytical solution of the impurity states in the radial wave function and electronic probability distribution . Impurities present in the center of the ring , the electron energy levels are reduced, the presence of impurities in the ground state of the excited state is relatively small . With quantum ring within the increase of the radius ( outer radius unchanged) , the influence of impurities decreases. Impurities in the center barrier moves , its location closer the quantum ring barrier edge , the ground state energy of the impurity states in the lower , and reduce the greater the degree . Second, we use the transfer matrix method to study the transport properties of the Aharonov- Bohm ( AB ) ring . We found no impurity the the AB ring channel angle change when the resonant peak splitting ; impurities in the center annular channel angle of the impact of the changes on the resonance peak splitting effect than when impurities more apparent , but the impurity the presence or absence does not affect the resonance peak suppression phenomenon . Same as the width of the ring, the inner radius is larger , the smaller the influence of impurities on the nature of the tunneling .

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