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arXiv 1102.5311cond-mat.mes-hall
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硅量子限制纳米结构中的工程谷轨分裂

Engineered valley-orbit splittings in quantum confined nanostructures in silicon

R. Rahman, J. Verduijn, N. Kharche, G. P. Lansbergen, G. Klimeck, L. C. L. Hollenberg, S. Rogge

摘要:

在硅量子电子学中,在少电子状态下的一个重要挑战是由于硅中存在的导带的多谷简并,在3D量子限制纳米结构中的基态和激发轨道态之间的潜在小的能隙。理解“谷轨道”(VO)间隙对于硅量子比特是必不可少的,因为大的VO间隙可以防止量子比特状态泄漏到更高维的希尔伯特空间中。VO间隙根据量子限制而显著变化,并且可以通过外部电场来设计。在这项工作中,我们调查VO分裂实验和理论上的限制制度的范围。本文报道了用激发态输运谱测量硅量子点和施主器件中VO的分裂。这些结果是由大规模的原子紧束缚计算,涉及超过100万个原子计算VO分裂作为电场,施主深度和表面无序的函数的基础。这些结果提供了一个全面的图片的VO分裂,可以通过量子工程实现的范围。

英文摘要:

An important challenge in silicon quantum electronics in the few electron regime is the potentially small energy gap between the ground and excited orbital states in 3D quantum confined nanostructures due to the multiple valley degeneracies of the conduction band present in silicon. Understanding the "valley-orbit" (VO) gap is essential for silicon qubits, as a large VO gap prevents leakage of the qubit states into a higher dimensional Hilbert space. The VO gap varies considerably depending on quantum confinement, and can be engineered by external electric fields. In this work we investigate VO splitting experimentally and theoretically in a range of confinement regimes. We report measurements of the VO splitting in silicon quantum dot and donor devices through excited state transport spectroscopy. These results are underpinned by large-scale atomistic tight-binding calculations involving over 1 million atoms to compute VO splittings as functions of electric fields, donor depths, and surface disorder. The results provide a comprehensive picture of the range of VO splittings that can be achieved through quantum engineering.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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