Collaborative Research: Multi-configurational Methods for Charge Transport in Nanoscale Electronics

罗文大学的Erik Hoy教授和巴特勒大学的Andrew Sand教授获得了化学系化学理论、模型和计算方法（CTMC）项目的奖励，以表征量子水平上的新型电荷输运过程。了解电荷输运对于追求对国家长期经济成功至关重要的领域的新发展至关重要，包括电子、太阳能和材料开发。纳米级有机电子器件显示出独特的电荷传输特性，可用于设计改进的电子器件（如晶体管、电阻器），但使用现有的计算方法描述许多这些器件中的电荷传输是具有挑战性的。罗文和巴特勒的联合团队将开发新的计算工具，用于生成基于非经典电荷输运效应的下一代电子设备所需的电荷输运数据。开发的计算工具将被纳入OpenMolcas软件包，该软件包广泛用于教育和研究工作。巴特勒大学和罗文大学都对本科教育做出了强有力的承诺，这个项目的核心教育成果是培养适合学术或行业职位的从事计算机工作的本科生。通过与导师计划和当地社区大学的学生招募合作伙伴关系，该项目为来自非传统背景和计算科学中代表性不足的群体的学生提供了研究途径。在单分子水平上运行的纳米级有机电子器件是提高科学界对量子水平上电荷输运理解的关键实验平台。单分子器件是将单个有机分子与金属或碳基电极结合而成的，它有可能成为下一代晶体管、电阻器和纳米级电子器件开关的基础。我们对纳米电子学中非经典电荷输运效应的理论理解仍然存在很大的差距，例如随着分子长度的增加而预期电导衰减的逆转。造成这种情况的一个关键原因是现有的传输方法对电子-电子相互作用（电子相关）的处理有限，特别是强/多参考相关。为了解决这个问题，Hoy/Sand研究团队将基于多组态对密度泛函理论（MC-PDFT）和非平衡格林函数形式主义（NEGF），开发全量子多组态电荷输运方法。主要目标包括开发新的基于mc - pdft的有效哈密顿量和多构型格林函数输运理论的自一致优化方案。将这些发展集成到一个开源的模块化Python框架中，可以表征量子输运现象中的多参考相关效应。利用这些NEGF-MCPDFT方法，该团队将研究包括反向电导衰减、库仑阻塞和近道共振在内的问题，以增强科学界对量子电荷输运现象的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Professors Erik Hoy of Rowan University and Andrew Sand of Butler University are supported by an award from the Chemical Theory, Models and Computational Methods (CTMC) program in the Division of Chemistry to characterize novel charge transport processes at the quantum level. Understanding charge transport is vital to pursuing new developments in areas considered critically important to long-term national economic success including electronics, solar energy, and materials development. Nanoscale organic electronic devices display unique charge transport properties that can be used to design improved electronic devices (ex. transistors, resistors), but it is challenging to describe charge transport in many of these devices using existing computational methods. The joint Rowan and Butler team will develop new computational tools for generating the charge transport data needed to design the next generation of electronic devices based on non-classical charge transport effects. The developed computational tools will be incorporated into the OpenMolcas software package, which is widely used in both educational and research efforts. Both Butler University and Rowan University have strong commitments to undergraduate education, and a core educational outcome of this project is the development of computationally-engaged undergraduate students fit for either academic or industry positions. Through student recruitment partnerships with mentorship programs and local community colleges, this project provides a pathway into research for students from non-traditional backgrounds and underrepresented groups in the computational sciences.Nanoscale organic electronic devices that operate at the single-molecule level are a key experimental platform for enhancing the scientific community’s understanding of charge transport at the quantum level. Created by combining single organic molecules with metal or carbon-based electrodes, single-molecule devices hold the potential to be the foundation for the next generation of transistors, resistors, and switches for nanoscale electronics. Large gaps remain in our theoretical understanding of non-classical charge transport effects in nanoscale electronics such as the reversal of the expected electrical conductance decay with increasing molecular length. A key reason for this is the limited treatment of electron-electron interactions (electron correlation) by existing transport methods particularly strong/multireference correlation. To resolve this, the Hoy/Sand research team will develop a fully-quantum family of multiconfigurational charge transport methods based on multiconfiguration pair density functional theory (MC-PDFT) combined with the non-equilibrium Green’s function formalism (NEGF). Key objectives include the development of new MC-PDFT-based effective Hamiltonians and self-consistent optimization schemes for multiconfigurational Green’s function transport theories. The integration of these developments within an open-source modular Python framework allows for the characterization of multireference correlation effects in quantum transport phenomena. Using these NEGF-MCPDFT methodologies, the team will investigate including reversed conductance decay, Coulomb blockades, and Kondo Resonances to enhance the scientific community’s understanding of quantum charge transport phenomena.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.