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arXiv 0707.3897cond-mat.supr-concond-mat.str-el
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量子点阵列的约瑟夫森效应

Josephson effect through a quantum dot array

F. S. Bergeret, A. Levy Yeyati, A. Martin-Rodero

摘要:

我们分析了串联在超导电极之间的量子点阵列的基态性质。这个系统是由一个有限的哈伯德链两端耦合到BCS超导体。基态的计算采用Lanczos算法,在低能理论中,体超导体被有效的局部对势所取代。我们研究的约瑟夫森耦合($π$结的行为)作为模型参数的函数的符号反转的条件。结果以相图的形式呈现,该相图提供了随着系统尺寸的增加而对总趋势的直接总体看法,表现出强烈的奇偶效应。自旋-自旋关联函数和局部电荷的分析进一步深入了解的基态的性质,以及它是如何被转化的超导性的存在下,在铅。最后,我们研究了约瑟夫森电流与系统尺寸的缩放,并将这些结果与以前的计算约瑟夫森输运通过Luttinger液体。

英文摘要:

We analyze the ground state properties of an array of quantum dots connected in series between superconducting electrodes. This system is represented by a finite Hubbard chain coupled at both ends to BCS superconductors. The ground state is obtained using the Lanczos algorithm within a low energy theory in which the bulk superconductors are replaced by effective local pairing potentials. We study the conditions for the inversion of the sign of the Josephson coupling ($π$-junction behavior) as a function of the model parameters. Results are presented in the form of phase diagrams which provide a direct overall view of the general trends as the size of the system is increased, exhibiting a strong even-odd effect. The analysis of the spin-spin correlation functions and local charges give further insight into the nature of the ground state and how it is transformed by the presence of superconductivity in the leads. Finally we study the scaling of the Josephson current with the system size and relate these results with previous calculations of Josephson transport through a Luttinger liquid.

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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