论文标题
基于Kagome钒的超导体观察到的Higgs-Leggett机制
Higgs-Leggett mechanism for the elusive 6e superconductivity observed in Kagome vanadium-based superconductors
论文作者
论文摘要
在Kagome结构化超导体CSV_3SB_5上进行的一个小公园实验显示出显着的电阻振荡，而周期\ phi0/3 = hc/6e。在这里，我们基于涉及三个2E超导率（SC）阶阶参数的理论进行分析，该参数与连接六边形布里鲁因区域的三个相互晶格向量相关。在环形几何形状中，我们揭示了一系列亚稳态状态，一个SC阶参数的相位比环周围的其他两个相比，在\ phi0/3的整数倍数处产生局部自由能最小值。有趣的是，与Z_2手性相关的基础状态是至关重要的，而Higgs-Leggett机制稳定了手性域之间的域壁（DW）。在低温下，DW被从系统中排出，仅在ϕ_0的整数倍数处产生自由能最小值。我们的理论解释了在实验中成功观察到的6E SC，这为接近kagome超导体的丰富物理学打开了一扇门。
A recent Little-Parks experiment on Kagome-structured superconductor CsV_3Sb_5 demonstrated remarkable resistance oscillations with period \phi0/3=hc/6e. Here, we perform analysis based on a theory involving three 2e superconductivity (SC) order parameters associated with the three reciprocal lattice vectors which connect M points of the hexagonal Brillouin zone. In a ring geometry we unveil that, as a series of metastable states, phase of one SC order parameter winds 2πmore or less than the other two ones around the ring, which yields local free energy minima at integer multiples of \phi0/3. Intriguingly, the ground-state degeneracy associated with a Z_2 chirality is crucial, and the Higgs-Leggett mechanism stabilizes domain walls (DW) between chiral domains. At low temperatures DW are expelled from the system resulting in free energy minima only at integer multiples of ϕ_0. Our theory explains successfully the 6e SC observed in experiments, which opens a door for approaching rich physics of Kagome superconductors.
