Christov Ivan P
Physics Department, Sofia University, 1164 Sofia, Bulgaria.
Entropy (Basel). 2023 Sep 8;25(9):1308. doi: 10.3390/e25091308.
The quantum entanglement entropy of the electrons in a one-dimensional hydrogen molecule is quantified locally using an appropriate partitioning of the two-dimensional configuration space. Both the global and the local entanglement entropy exhibit a monotonic increase when increasing the inter-nuclear distance, while the local entropy remains peaked in the middle between the nuclei with its width decreasing. Our findings show that at the inter-nuclear distance where a stable hydrogen molecule is formed, the quantum entropy shows no peculiarity thus indicating that the entropy and the energy measures display different sensitivity with respect to the interaction between the two identical electrons involved. One possible explanation is that the calculation of the quantum entropy does not account explicitly for the distance between the nuclei, which contrasts to the total energy calculation where the energy minimum depends decisively on that distance. The numerically exact and the time-dependent quantum Monte Carlo calculations show close results.
利用二维构型空间的适当划分，对一维氢分子中电子的量子纠缠熵进行局域量化。当增加核间距时，全局和局域纠缠熵均呈现单调增加，而局域熵在核中间保持峰值，其宽度减小。我们的研究结果表明，在形成稳定氢分子的核间距处，量子熵没有特殊性，这表明熵和能量度量对所涉及的两个相同电子之间的相互作用表现出不同的敏感性。一种可能的解释是，量子熵的计算没有明确考虑核之间的距离，这与总能量计算形成对比，在总能量计算中，能量最小值决定性地取决于该距离。数值精确的和含时量子蒙特卡罗计算结果相近。
