Interaction Effects in the Mesoscopic Regime: A Quantum Monte Carlo Study of Irregular Quantum Dots
Interaction Effects in the Mesoscopic Regime: A Quantum Monte Carlo Study of Irregular Quantum Dots
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介观区域中的相互作用效应：不规则量子点的量子蒙特卡罗研究
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
H. Baranger
中科院分区：
文献类型：
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作者：
A. Ghosal;C. Umrigar;Hong;D. Ullmo;H. Baranger
通过研究孤立的不规则量子点的基态性质，我们解决了精确处理介观体系中相互作用效应的问题。用量子Monte Carlo方法计算了基态自旋和加成能的分布。与局域自旋密度泛函理论相比，量子蒙特卡罗方法得到的高自旋态的几率降低，并且在附加能量上的奇偶交替稍大。在这两种方法中，偶数/奇数效应随着电子数量的增加而变小，与理论上对大点的理解相反。我们认为局域自旋密度近似过度预测了量子点中相互作用的影响。
We address the issue of accurately treating interaction eff ects in the mesoscopic regime by investigating the ground state properties of isolated irregular quantum dots . Quantum Monte Carlo techniques are used to calculate the distributions of ground state spin and addition ene rgy. We find a reduced probability of high spin and a somewhat larger even/odd alternation in the addition energy from quantum Monte Carlo than in local spin density functional theory. In both approaches, the even/odd effect gets smaller with increasing number of electrons, contrary to the theoretical understanding of large dots. We argue that the local spin density approximation over predicts the effects of interactions in quantum dots.