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arXiv 1401.3763cond-mat.supr-con
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反铁磁弱链中压力诱导的$0-π$相变和超电流渡越

Pressure-Induced $0-π$ Transitions and Supercurrent Crossover in Antiferromagnetic Weak Links

H. Enoksen, J. Linder, A. Sudbø

摘要:

我们自洽地计算约瑟夫森电流在超导体-反铁磁-超导体结使用晶格模型,专注于$0-π$转变时发生的反铁磁区域的宽度从偶数到奇数的晶格位置的变化。以前的研究预测$0-π$过渡时,交替的偶数和奇数的网站足够强的反铁磁秩序。我们研究数值的阈值的大小发生这种情况,并解释其存在背后的物理学方面的相移回升的准粒子构成的反铁磁体中的超电流。此外,我们表明,这个阈值允许\textit{pressure-induced $0-π$ transitions}通过破坏费米表面的反铁磁嵌套特性,一种在铁磁约瑟夫森结中没有对应物的现象,{提供了一种新的方式来调谐约瑟夫森结的量子基态,而不需要多个样品。

英文摘要:

We compute self-consistently the Josephson current in a superconductor-antiferromagnet-superconductor junction using a lattice model, focusing on $0-π$ transitions occurring when the width of the antiferromagnetic region changes from an even to an odd number of lattice sites. Previous studies predicted $0-π$ transitions when alternating between an even and an odd number of sites for sufficiently strong antiferromagnetic order. We study numerically the magnitude of the threshold value for this to occur, and also explain the physics behind its existence in terms of the phase-shifts picked up by the quasiparticles constituting the supercurrent in the antiferromagnet. Moreover, we show that this threshold value allows for \textit{pressure-induced $0-π$ transitions} by destroying the antiferromagnetic nesting properties of the Fermi surface, a phenomenon which has no counterpart in ferromagnetic Josephson junctions, {offering a new way to tune the quantum ground state of a Josephson junction without the need of multiple samples.

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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