• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Quantum Monte Carlo for correlated out-of-equilibrium nanoelectronic devices
【24h】

Quantum Monte Carlo for correlated out-of-equilibrium nanoelectronic devices

机译：量子蒙特卡罗用于相关的失衡纳米电子器件

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We present a simple, general purpose, quantum Monte Carlo algorithm for out-of-equilibrium interacting nanoelectronic systems. It allows one to systematically compute the expansion of any physical observable (such as current or density) in powers of the electron-electron interaction coupling constant U. It is based on the out-of-equilibrium Keldysh Green's function formalism in real-time and corresponds to evaluating all the Feynman diagrams to a given order U~n (up to n = 15 in the present work). A key idea is to explicitly sum over the Keldysh indices in order to enforce the unitarity of the time evolution. The coefficients of the expansion can easily be obtained for long-time, stationary regimes, even at zero temperature. We then illustrate our approach with an application to the Anderson model, an archetype interacting mesoscopic system. We recover various results of the literature such as the spin susceptibility or the "Kondo ridge" in the current-voltage characteristics. In this case, we found the Monte Carlo free of the sign problem even at zero temperature, in the stationary regime and in absence of a particle-hole symmetry. The main limitation of the method is the lack of convergence of the expansion in U for large U, i.e., a mathematical property of the model rather than a limitation of the Monte Carlo algorithm. Standard extrapolation methods of divergent series can be used to evaluate the series in the strong correlation regime.
机译：我们提出了一种非平衡相互作用纳米电子系统的简单通用量子蒙特卡洛算法。它允许人们系统地计算电子-电子相互作用耦合常数U的幂内的任何物理可观察到的（例如电流或密度）的扩展。它基于非平衡Keldysh Green函数形式主义的实时性和对应于将所有费曼图评估为给定的阶数U〜n（在当前工作中最多n = 15）。一个关键的想法是显式求和Keldysh指数，以增强时间演化的统一性。即使在零温度下，对于长时间的固定状态，也可以轻松获得膨胀系数。然后，我们将其应用于Anderson模型（原型交互介观系统）来说明我们的方法。我们在电流-电压特性中恢复了自旋磁化率或“近藤脊”等文献的各种结果。在这种情况下，我们发现即使在零温度，静止状态且没有粒子-孔对称性的情况下，蒙特卡洛也没有符号问题。该方法的主要局限性在于，对于大的U，U的展开缺乏收敛性，即模型的数学特性，而不是Monte Carlo算法的局限。发散级数的标准外推方法可用于评估强相关方案中的级数。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号