Simplified model of calculating heterojunctionband

本论文的工作可分两部分。第一部分是关于异质结带阶的研究。第二部分研究周期性磁场下单量子阱中电子的能带结构。 在带阶研究中，我们主要对应变层异质结的带阶进行研究。首先采用基于密度泛函理论框架下的模守恒赝势法计算得到体半导体材料的能带结构，接着我们把平均键能方法推广应用于应变层异质结的价带和导带带阶研究。通过平均带阶参数形变势和研究带阶参数随应变状态的变化关系，发现平均带阶参数在不同应变状态下基本上保持不变，从而建立了异质结带阶计算的简化模型。这样，在应变层带阶参数的计算中，只需计算其应变前体材料的带阶参数值并引用形变势和SO裂距的实验值，通过简便的代数运算即可得到应变层，从而方便地预测不同应变...This thesis consists of two parts. In the first part we studied band offsets of heterojunctions. In the second part the electronic band structure of single quantum well in periodic magnetic field was investigated. In the study of band offset, we focused our attention on the band offsets of strained-layer heterojunctions. Firstly, we made use of norm-conserving pseudopotentials within local-de...学位：理学硕士院系专业：物理与机电工程学院物理学系_理论物理学号：19982400

Electronic Band Structure of GaAs/Al_xGa_(1-x) As Single Quantum Well in Periodic Magnetic Field

为了研究外磁场对量子阱中电子的能带结构的影响 ,采取了一种简单的可解析求解的模型 ,研究了周期性磁场下的 Ga As/ Alx Ga1 -x As单量子阱中电子的能带结构 ,发现在周期性磁场的作用下 ,在 z方向上的能量是分立的量子化能级 ,而原来在 x- y平面内连续的能级分裂成分立的一系列许可带 ,但是在 x方向上能量仍然是连续的 ,同时对其能带的特点和形成机制进行探讨In order to investigate the effect of an external magnetic field on electronic band structure of quantum wells, we employ a simple solvable model to investigate electronic band structure of GaAs/AlxGa1-x As single quantum well in a periodic magnetic field. Through careful study, we find that under the periodic magnetic field, the energies of z direction are certain quantum energy steps, and the energies of xy plane which are continuous originally are divided into various permissive bands, but the energies of x direction are still continuous. Meanwhile, the characteristics of electronic band structure and its formative mechanism are discussed.福建省自然科学基金资助项目!(E991005

固/液及固/气界面铑表面氧化物还原的现场拉曼光谱研究

本文通过制备具有表面拉曼增强活性的金属Rh基底 ,将表面拉曼光谱技术拓展到固 液和固 气体系的吸附和反应研究。同时也初步了解了上述两种环境下Rh表面氧化物的还原情况。结果表明 ,无论是在固 液还是固 气体系 ,激光在还原过程中起着重要的作用。通过两个体系所得结果的比较 ,可以看到这两种体系中金属Rh表面氧化物还原行为的相似和不

Simplified Model of Average-bond Energy Method in Calculating Band Offset of Strained-layer Heterojunction

将平均键能方法推广应用于应变层异质结的价带和导带阶研究。通过平均带阶参数形变势amv来研究带阶参数Emv随应变状态的变化关系 ,发现平均带阶参数Emv .av=Em-Ev .av在不同应变状态下基本上保持不变。因此 ,在应变层带阶参数Emv的计算中 ,只需计算其发生应变前体材料的带阶参数Emv .0 值并引用形变势b和SO裂距Δ0 的实验值 ,通过简便的代数运算即可得到应变层的Emv值 ,从而方便地预言不同应变层异质结的价带带阶。本文引入带隙形变势aGap来描述带隙改变量ΔEg 随应变状态的变化。由导带带阶和价带带阶的关系ΔEc=ΔEg+ΔEv 可以求出不同应变情况下的导带带阶。福建省自然科学基金资助项目 (E990 0 0 5

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies