Full configuration interaction simulations of exchange-coupled donors in silicon using multi-valley effective mass theory - Raw data sets and plot routines

Donor spin in silicon have achieved record values of coherence times and single-qubit gate fidelities. The next stage of development involves demonstrating high-fidelity two-qubit logic gates, where the most natural coupling is the exchange interaction. To aid the efficient design of scalable donor-based quantum processors, we model the two-electron wave function using a full configuration interaction method within a multi-valley effective mass theory. We exploit the high computational efficiency of our code to investigate the exchange interaction, valley population, and electron densities for two phosphorus donors in a wide range of lattice positions, orientations, and as a function of applied electric fields. The outcomes are visualized with interactive images where donor positions can be swept while watching the valley and orbital components evolve accordingly. Our results provide a physically intuitive and quantitatively accurate understanding of the placement and tuning criteria necessary to achieve high-fidelity two-qubit gates with donors in silicon. Here we provide the raw data sets and plot routines.

硅中的施主自旋（donor spin）已实现相干时间与单量子比特门保真度的纪录级数值。后续研发阶段需实现高保真度双量子比特逻辑门，而其最自然的耦合机制即为交换相互作用（exchange interaction）。为助力可规模化施主基量子处理器的高效设计，我们基于多谷有效质量理论（multi-valley effective mass theory），采用全组态相互作用（full configuration interaction）方法对双电子波函数进行建模。我们利用代码极高的计算效率，针对大范围晶格位置、取向条件下的两个磷施主，以及外加电场的变化情况，研究了交换相互作用、谷占据数与电子密度分布。研究结果通过交互式图像进行可视化展示：可在拖动调整施主位置的同时，直观观察谷分量与轨道分量的动态演化过程。本研究结果为实现硅基施主高保真双量子比特门所需的位置排布与调谐准则，提供了兼具物理直观性与定量准确性的认知基础。本文将提供原始数据集与绘图脚本。