Effects of quantum noise on dephasing in mesoscopic systems

量子噪声对介观系统相移的影响

• 批准号: 185960027
• 负责人: Professor Dr. Jan von Delft
• 金额: --
• 依托单位: Lehrstuhl für Theoretische Festkörperphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/185960027?language=en
• 关键词: Effects; quantum; noise; dephasing; mesoscopic

We propose to study the effects of quantum noise on dephasing due to electronelectron interactions in mesoscopic disordered systems, in the context of weak localization (WL) and universal conductance fluctuations (UCFs). In such systems, interactions can be described via a fluctuating effective noise field affecting the quantum mechanical phase of electron wave functions. The phase space for energy transfer between conduction electrons and this noise field, however, is restricted by Pauli blocking and hence depends on the temperature T. This very fundamental effect can be accounted for by using an effective quantum noise field with a nonzero noise correlation time, TT 1/T (whereas the commonly-used classical noise field has TT = 0). We will study two types of systems for which using TT ≠ 0 is essential: (i) Complex geometries such as rings and grids constructed from quasi-1D wires, characterized by a Thouless energy ETh (the inverse time for traversing a ring or a grid plaquette); and (ii) dephasing in external AC fields, characterized by an AC frequency ωac. For these, the temperature-dependence of the dephasing time Tφ(T) changes qualitatively once T drops below ETh or ωac, with experimentally measurable consequences for phenomena involving WL and UCFs.

我们建议在弱定位（WL）和通用电导波动（UCFS）的背景下，研究量子噪声对介质无序系统中电seption相互作用引起的脱去的影响。在这样的系统中，可以通过影响电子波函数的量子机械相的有效噪声场来描述相互作用。但是，传导电子之间的能量传递的相空间受Pauli阻断的限制，因此取决于温度T。可以通过使用具有非零噪声相关时间的有效量子噪声场来解决这种基本效果，而非零噪声相关时间TT 1/T（而常用的经典噪声场具有TT = 0）。我们将研究使用TT≠0的两种类型的系统至关重要：（i）复杂的几何形状，例如由准1D线构建的环和网格，其特征是无效的能量ETH（横穿环或网格plaquette的相反时间）； （ii）以交流频率ωAC为特征在外部AC场中进行脱去。为此，一旦t降至ETH或ωAC以下，质量tm（t）的温度依赖性变化，对涉及WL和UCF的现象的实验可测量后果。

项目成果

Quantum corrections to the polarizability and dephasing in isolated disordered metals

对孤立无序金属的极化率和相移的量子校正

• DOI: 10.1103/physrevb.88.024201
• 发表时间: 2013
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: M. Treiber;P. M. Ostrovsky;O. M. Yevtushenko;J. von Delft;I. V. Lerner
• 通讯作者: I. V. Lerner

Transport and dephasing in a quantum dot: Multiply connected graph model

量子点中的传输和移相：多重连通图模型

• DOI: 10.1002/andp.201100258
• 发表时间: 2012
• 期刊: Annalen der Physik
• 影响因子: 2.4
• 作者: M. Treiber;O. M. Yevtushenko;F. Marquardt;J. von Delft;I. V. Lerner
• 通讯作者: I. V. Lerner