Quantum dynamics, dissipation, and asymmetry effects in quantum dot arrays
Quantum dynamics, dissipation, and asymmetry effects in quantum dot arrays
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量子点阵列中的量子动力学、耗散和不对称效应
DOI：
10.1103/physrevb.66.235305
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发表时间：
2002
影响因子：
3.7
通讯作者：
S. Ulloa
中科院分区：
文献类型：
--
作者：
F. Rojas;E. Cota;S. Ulloa
我们研究了外部驱动场下耗散和结构缺陷对具有移动电荷的量子点阵列的时间演化的作用。这些结构被提出为量子点元胞自动机，表现出有趣的量子动力学，我们用密度矩阵的运动方程来描述。使用开放系统方法，我们研究不对称性和微观电子声子相互作用对此类系统电荷分布（极化）的一般动态行为的作用。我们发现，系统对驱动场的响应在低温（和/或弱声子耦合）下得到改善，然后随着温度和不对称性的增加而恶化。除了研究偏振的时间演化之外，我们还探索了系统的线性熵，以便进一步深入了解相干演化和耗散过程之间的竞争。
We study the role of dissipation and structural defects on the time evolution of quantum dot arrays with mobile charges under external driving fields. These structures, proposed as quantum dot cellular automata, exhibit interesting quantum dynamics which we describe in terms of equations of motion for the density matrix. Using an open system approach, we study the role of asymmetries and the microscopic electron-phonon interaction on the general dynamical behavior of the charge distribution (polarization) of such systems. We find that the system response to the driving field is improved at low temperatures (and/or weak phonon coupling), before deteriorating as temperature and asymmetry increase. In addition to the study of the time evolution of polarization, we explore the linear entropy of the system in order to gain further insights into the competition between coherent evolution and dissipative processes.