Correlation effects in quantum dots and wires

量子点和量子线的相关效应

• 批准号: 35776612
• 负责人: Professor Dr. Volker Meden
• 金额: --
• 依托单位: Institut für Festkörperphysik
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/35776612?language=en
• 关键词: Correlation; effects; quantum; dots; wires

In this project we investigate correlation effects in (quasi) one-dimensional quantum wires and in “zero”-dimensional quantum dots with a particular focus on the transport properties of such systems in the linear response regime and singleparticle spectral properties. We have successfully applied a truncation scheme leading to a static self-energy to problems of direct experimental relevance (“phase lapse puzzle” and charging of multi-level dots, Josephson current through correlated quantum dot). The static approximation can only be used in situation in which inelastic processes are irrelevant (e.g. temperatur T = 0 conductance). We thus extended the truncation scheme and kept the frequency dependence of the two-particle vertex which within the one-particle irreducible functional RG leads to a frequency dependent self-energy. We applied this scheme to study the singleimpurity Anderson model (in the appropriate parameter regime dominated by spin fluctuations) and the interacting resonant level model (dominated by charge fluctuations). We discussed the merits and drawbacks of this scheme. We will try to improve on the latter (higher-order corrections). Next we will use the frequency dependent approximation to investigate more complex systems of quantum dots showing a physics which is dominated by the interplay of the Kondo effect and other interactions (such as the RKKY). We will extend the frequency dependent scheme to study quantum wires. An interesting question is the crossover between bulk and boundary Luttinger liquid physics. Finally, we will use the frequency dependent scheme to study fermionic systems coupled to bosons (e.g. local electronic levels coupled to phonons.)

在该项目中，我们研究了（准）一维量子线和“零”维量子点中的相关效应，在线性响应方案和单粒子光谱特性中特别关注此类系统的传输特性。我们已经成功地应用了截断方案，从而导致直接实验相关性的问题（“相位衰变拼图”和多级点的充电，约瑟夫森通过相关量子点的电流）。静态近似只能在非弹性过程无关的情况下使用（例如温度t = 0电导）。因此，我们扩展了截断方案，并保持两粒子顶点的频率依赖性，该顶点在一个粒子不可减至的功能性RG中导致频率依赖性自我能量。我们应用了该方案来研究单个影响的安德森模型（以自旋波动为主的适当参数制度）和相互作用的谐振水平模型（由电荷波动主导）。我们讨论了该计划的优点和缺点。我们将尝试改进以后的（高阶校正）。接下来，我们将使用频率依赖性近似来研究更复杂的量子点系统，以显示物理学，该物理是由近托效应和其他相互作用（例如rkky）的相互作用主导的。我们将扩展频率依赖方案以研究量子线。一个有趣的问题是散装和边界Luttinger液体物理学之间的交叉。最后，我们将使用频率依赖方案研究耦合到玻色子的费米子系统（例如，局部电子水平与声子耦合。）。