量子计算方法对使用经典影子的固定节点蒙特卡洛
Nick S Blunt1, Laura Caune1, Javiera Quiroz-Fernandez1,2
1Riverlane, Cambridge CB2 3BZ, U.K.
Journal of chemical theory and computation
|February 5, 2025
概括
本研究介绍了一种固定节点的蒙特卡罗方法,通过避免指数级缩放问题来改进量子蒙特卡罗 (QMC) 计算. 虽然对化学准确性有希望,但高采样成本建议谨慎使用超越传统QMC方法的性能.
科学领域:
- 量子计算是一种量子计算.
- 计算化学是一种计算化学.
- 电子结构理论 电子结构理论
背景情况:
- 量子蒙特卡洛 (QMC) 方法为电子结构问题提供了高精度.
- 试验波函数的精度限制了QMC的精度.
- 之前的工作使用了辅助场QMC (AFQMC) 的量子计算机,但面临着指数级后处理.
研究的目的:
- 开发一种量子蒙特卡洛方法,避免指数缩放.
- 为了提高效率,研究一种固定节点的蒙特卡洛方法.
- 为了比较AFQMC和固定节点方法的性能和稳定性.
主要方法:
- 采用基于完整配置交互QMC的固定节点蒙特卡洛方法.
- 将该方法应用于当地单元集群Jastrow ansatz.
- 在使用高达12个量子位的H4,铁和分子上进行测试,考虑到电路级噪声.
主要成果:
- 新的固定节点方法避免了以前量子辅助AFQMC的指数扩展.
- 辅助场QMC (AFQMC) 显示出比固定节点方法更强大的错误稳定性.
- 固定节点能量的推算减少了方法之间的差异.
- 为了达到化学精度,即使在小型系统中,也需要高的采样成本.
结论:
- 开发的固定节点方法通过避免指数级扩展,为量子辅助AFQMC提供了替代方案.
- 尽管化学准确性有潜力,但高采样成本对实际应用构成挑战.
- 需要进一步的研究来评估超越传统QMC方法的可行性.
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