arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1608.00409cond-mat.supr-con
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螺旋$p$波约瑟夫森结中的可调谐基态

Tunable ground states in helical $p$-wave Josephson junctions

Qiang Cheng, Kunhua Zhang, Dongyang Yu, Chongju Chen, Yinhan Zhang, Biao Jin

摘要:

本文利用准经典格林函数和广义Riccati参数化方法研究了由螺旋型$p$波超导体组成的新型约瑟夫森结,这种超导体具有$k_{x}\hat{x}\pm k_{y}\hat{y}$和$k_{y}\hat{x}\pm k_{x}\hat{y}$配对对称性.结可以具有丰富的基态:$π$相、$0+π$相、$φ_{0}$相和$φ$相。相变可以通过旋转铁磁界面的磁化强度来调节。我们提出的相图中的参数空间形成的磁化方向或由界面电位的大小。通过数值计算,从电流-相位关系中总结出了形成富相的最低阶电流的选择规律。我们用${\bf{d}}$ -矢量和磁化强度构造了一个Ginzburg-Landau型的自由能,它不仅揭示了自旋三重态超导和铁磁性的相互作用形式,而且可以直接导出选择定则.此外,Andreev束缚态的能量和新颖的对称性的电流相位关系也进行了研究。我们的结果对预测新的约瑟夫森相位和量子电路的设计都有帮助。

英文摘要:

We study new types of Josephson junctions composed of helical $p$-wave superconductors with $k_{x}\hat{x}\pm k_{y}\hat{y}$ and $k_{y}\hat{x}\pm k_{x}\hat{y}$-pairing symmetries using quasiclassical Green's functions with the generalized Riccati parametrization. The junctions can host rich ground states: $π$ phase, $0+π$ phase, $φ_{0}$ phase and $φ$ phase. The phase transition can be tuned by rotating the magnetization in the ferromagnetic interface. We present the phase diagrams in the parameter space formed by the orientation of the magnetization or by the magnitude of the interfacial potentials. The selection rules for the lowest order current which are responsible for the formation of the rich phases are summarized from the current-phase relations based on the numerical calculation. We construct a Ginzburg-Landau type of free energy for the junctions with ${\bf{d}}$-vectors and the magnetization, which not only reveals the interaction forms of spin-triplet superconductivity and ferromagnetism but also can directly leads to the selection rules. In addition, the energies of the Andreev bound states and the novel symmetries in the current-phase relations are also investigated. Our results are helpful both in the prediction of the novel Josephson phases and in the design of the quantum circuits.

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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