纳米结构物理学—1.pptVIP

* 纳米结构物理学 课程内容 纳米科学概论, 低维体系量子力学 固体物理, 表面/界面科学及材料生长简介 纳米结构常用分析与制备方法 纳米线(管,带,杆) 团簇与晶粒 磁性纳米结构及自旋电子学 1 nm = 10-9 m = 10-3 ?m = 10 ? 纳米结构 (Nanostructures): material systems with length scale of ~ 1-100 nm in at least one dimension 2-D: quantum wells, thin films, 2-D electron gas 1-D: quantum wires, nanowires, nanotubes, nanorods 0-D: quantum dots, macro-molecules, clusters, nano-crystallites Between individual atoms/molecules and macroscopic bulk materials: Mesoscopic structures (介观结构), with distinct properties not available from atoms or bulk crystals 类型 材料性质随体系尺度的变化：量变到质变 Quantum confinement: quantization and reduced dimensionality of electronic states Quantum coherence and de-coherence Surface/interface states Metastability, adjustable size and shape → Properties tunable High speed, compact density and efficiency Unique properties of nanostructures: Two approaches in our understanding and exploitation of material world: from the bottom up and from the top down The bottom-up approach: Atoms, simple molecules (well-understood sub-nm world) → Macro-molecules, polymers… → clusters, crystallites, nanowires, bio-molecules… The top-down approach: Bulk crystals → Discrete devices → Integrated circuits → LSI → VLSI → ULSI (~ 0.1-0.05 ?m) → ??? → Shrinking and shrinking into deep sub-0.1-?m 两种途径在纳米尺度相会 For up-to-date Edition visit 半导体工业路线图 Bottom-up approach can deal with systems consisting of ? 104 atoms quite accurately 纳米研究的目标 Search for new physical phenomena existing at nanoscales Fabricate nano-devices with novel functions Search for processes to fabricate nanostructures with high accuracy and low cost Explore new experimental and theoretical tools to study nanostructures Nanoscience nanotechnology: Multi-disciplinary and rapid-developing 现状与未来: 一个学术界，政府和产业部门高度重视的战略性研究领域 Quantum mechanics of low-dimensional systems Time-independent Schr?dinger equation: Free particle [with V(r) = 0], plane wave: ?(r , t) = A exp(ik·r - iEt