Electron counting statistics for non-additive environments
Electron counting statistics for non-additive environments
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DOI：
10.1063/1.5095838
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发表时间：
2019-08-07
影响因子：
4.4
通讯作者：
Nazir, Ahsan
中科院分区：
文献类型：
--
作者：
McConnell, Conor;Nazir, Ahsan
分子电子学是一门以分子作为电子元件结构基础的快速发展的学科。在这种设备中，感兴趣的系统同时耦合到多个环境是很常见的。在这里，我们考虑一个由双量子点（或分子）组成的模型，该模型与振动强耦合，与任意偏置电压下的两个电子引线弱耦合。强振动耦合使得将玻色子和电子环境简单地视为加性作用失效，就像在弱耦合状态或无限偏置下的平坦引线的情况一样。相反，利用反应坐标框架，我们将主要的振动耦合效应纳入一个扩大的系统哈密顿量。这使我们能够推导出引线耦合的非加性形式，该形式适当地解释了双点系统和振动之间的强和非马尔可夫耦合的影响。应用计数统计技术，我们跟踪了双点和电子引线之间的电子流，揭示了电子电流、噪声和Fano因子的强耦合和非加性效应。由AIP出版社授权出版。
Molecular electronics is a rapidly developing field focused on using molecules as the structural basis for electronic components. It is common in such devices for the system of interest to couple simultaneously to multiple environments. Here, we consider a model comprising a double quantum dot (or molecule) coupled strongly to vibrations and weakly to two electronic leads held at arbitrary bias voltage. The strong vibrational coupling invalidates treating the bosonic and electronic environments simply as acting additively, as would be the case in the weak coupling regime or for flat leads at infinite bias. Instead, making use of the reaction coordinate framework, we incorporate the dominant vibrational coupling effects within an enlarged system Hamiltonian. This allows us to derive a nonadditive form for the lead couplings that accounts properly for the influence of strong and non-Markovian coupling between the double dot system and the vibrations. Applying counting statistics techniques, we track electron flow between the double dot and the electronic leads, revealing both strong-coupling and nonadditive effects in the electron current, noise, and Fano factor. Published under license by AIP Publishing.