Decoherence of Molecular Spin Qubits

在化学系化学结构、动力学和机制(CSDM-A)计划的支持下，华盛顿大学的Stefan Stoll教授和他的研究小组正在研究量子比特(量子比特)的基本行为，量子比特是量子计算和量子传感等突破性量子信息应用所需的基本构建块。发展量子比特的一个根本挑战是它们的消相干，即它们随着时间的推移丢失信息的事实。斯托尔教授和他的研究小组正在通过开发和验证一个基于分子结构预测量子比特退相干的计算模型来应对这一挑战。该模型将对指导新型量子材料的化学设计产生广泛的影响。该项目的其他更广泛的影响包括为学生提供高级培训机会、外展活动和在线教育资源的传播，包括EPR光谱分析的开源软件。该项目的科学目标包括建模和理解导致分子电子自旋量子比特退相干的物理机制。为此，斯托尔教授领导的研究小组正致力于开发和验证一种新的计算方法，该方法根据分子自旋量子比特的空间结构来定量预测电子自旋退相干。第一性原理方法结合了密度泛函理论、分子动力学和多体自旋量子动力学。这种创新的方法及其定量预测将通过与各种分子自旋中心的脉冲EPR(电子顺磁共振)谱实验数据的比较来验证。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) Program in the Division of Chemistry, Professor Stefan Stoll and his research group at the University of Washington are studying the fundamental behavior of qubits (quantum bits), the essential building blocks needed for ground-breaking quantum information applications such as quantum computing and quantum sensing. A fundamental challenge in the development of qubits is their decoherence, i.e. the fact that they lose information over time. Professor Stoll and his research group are addressing this challenge by developing and validating a computational model that predicts qubit decoherence based on molecular structures. This model will have broad impact by guiding the chemical design of novel quantum materials. Additional broader impacts of the project include advanced training opportunities for students, outreach activities, and the dissemination of online educational resources, including an open-source software for EPR spectroscopy.The scientific goals of the project include modeling and understanding the physical mechanisms that cause decoherence of molecular electron spin qubits. For this purpose, the research team led by Professor Stoll is working to develop and validate a novel computational approach that quantitatively predicts electron spin decoherence in molecular spin qubits from their spatial structure. The first-principles approach combines density functional theory and molecular dynamics with many-body spin quantum dynamics. This innovative approach and its quantitative predictions will be validated by comparison with experimental data from pulse EPR (electron paramagnetic resonance) spectroscopy on a variety of molecular spin centers.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.