ITR: Advances of Simulation Algorithm of Quantum Manybody Transport in Steady State Nonequilibrium

ITR：稳态非平衡量子多体输运模拟算法研究进展

• 批准号: 0426826
• 负责人: Jong Han
• 金额: $ 58.5万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0426826&HistoricalAwards=false
• 关键词: ITR; Advances; Simulation; Algorithm; Quantum

This award was made on a proposal submitted to the Division of Materials Research under the Information Technology Research solicitation NSF-04-012. Research activities covered by this award fall under the National Priority Area, "Advances in Science and Engineering," and the Technical Focus Area, "Innovation in Computational Modeling or Simulation in Research." This award supports fundamental computational and theoretical research on nonequilibrium transport in quantum dots and nanostructures. On the nanometer length scale, high-bias nonequilibrium and quantum many-body effects are intimately coupled and conventional theories for transport in semiconductor devices become inadequate. The PI will develop a quantum simulation algorithm for steady state nonequilibrium systems. Quantum Monte Carlo simulations will be used to sample steady-state nonequilibrium ensembles governed by an effective quantum Hamiltonian that consists of the nanostructure Hamiltonian and the bias operator. The bias operator, written in terms of many-body scattering states, embodies the nonequilibrium boundary conditions of an open environment. Expectation values of time-independent operators can be calculated without analytic continuation.Quantum simulation in the far-from-equilibrium steady state has been lacking to date. The PI's method enables the determination of essential characteristics of steady-state transport, such as I-V curves. The algorithm is expected to continuously cover wide bias regimes from many-body coherent transport to one-body transport. With the flexibility of the quantum Monte Carlo algorithm, the PI plans to extend simulations to multi-dot and multi-level systems. The inter-site resonance, dephasing and voltage-drop will be investigated systematically. Non-local effects induced by the nonequilibrium boundary condition are included in a controlled manner. The PI's general algorithm may have broader impact on other fields that may contribute to future information technology, including: quantum information control, spintronics, quantum optics, and quantum computation. A confined system (eg. quantum dots) coupled to an open environment (eg. Metallic leads) constitutes a general problem of how quantum information is transported, dephased and reduced by the many-body interactions and the coupling to the environmental degrees of freedom. This work on quantum nonequilibrium systems may have further impact on chemistry and core electrical engineering. %%%This award was made on a proposal submitted to the Division of Materials Research under the Information Technology Research solicitation NSF-04-012. Research activities covered by this award fall under the National Priority Area, "Advances in Science and Engineering," and the Technical Focus Area, "Innovation in Computational Modeling or Simulation in Research." This award supports fundamental computational and theoretical research on nonequilibrium transport in quantum dots and other nanostructures. Electrons in materials such as quantum dots and nanostructures under the influence of strong electric fields are a system of strongly interacting particles that is far from equilibrium and presents a fundamental problem that is intellectually challenging. Such systems are not well understood and at the same time can form the basis for future technologies. The PI proposes to develop a new algorithm that he will use to study the interplay between interactions and the degree to which a system is out of equilibrium. In addition to algorithmic development, the use of the algorithm may impact future information technology.***

该奖项是根据信息技术研究招标NSF-04-012提交给材料研究部的提案。该奖项涵盖的研究活动属于国家优先领域，“科学与工程学的进步”以及技术重点领域，“计算建模或研究中的仿真创新”。该奖项支持量子点和纳米结构中非平衡运输的基本计算和理论研究。在纳米长度尺度上，高偏置非平衡和量子多体效应是密切耦合的，并且在半导体设备中运输的常规理论不足。 PI将开发用于稳态非平衡系统的量子模拟算法。量子蒙特卡洛模拟将用于采样由有效的量子哈密顿量管辖的稳态非平衡集合，由纳米结构哈密顿量和偏置操作员组成。偏置操作员以多体散射状态编写，体现了开放环境的非平衡边界条件。无需分析性延续就可以计算时间非依赖性操作员的期望值。迄今为止，远程平衡稳态中的Quantum模拟迄今为止一直缺乏。 PI的方法可以确定稳态运输的基本特征，例如I-V曲线。该算法有望连续涵盖从多体相干运输到一体运输的广泛偏见。凭借量子蒙特卡洛算法的灵活性，PI计划将模拟扩展到多点和多层系统。将系统研究地点间共振，脱落和电压滴滴。 由非平衡边界条件引起的非本地效应以受控方式包括在内。 PI的一般算法可能会对可能有助于未来信息技术的其他领域产生更大的影响，包括：量子信息控制，旋转型，量子光学计算和量子计算。与开放环境（例如金属线索）结合的限制系统（例如量子点）构成了一个普遍的问题，即通过多体相互作用以及耦合到环境自由度的量子信息如何运输，降低和减少量子信息。这项关于量子非平衡系统的工作可能会对化学和核心电气工程产生进一步的影响。该奖项是根据信息技术研究邀请NSF-04-012提交给材料研究部的提案。该奖项涵盖的研究活动属于国家优先领域，“科学与工程学的进步”以及技术重点领域，“计算建模或研究中的仿真创新”。该奖项支持量子点和其他纳米结构中非平衡运输的基本计算和理论研究。 在强电场的影响下，量子点和纳米结构等材料中的电子是一种强烈相互作用的颗粒系统，远非平衡，并且提出了一个基本问题，在智力上具有挑战性。这样的系统尚未得到充分的理解，同时也可以构成未来技术的基础。 PI建议开发一种新算法，他将使用该算法来研究相互作用与系统不平衡程度之间的相互作用。除了算法开发外，算法的使用可能会影响未来的信息技术。***