Photonic Weyl degeneracies in magnetized plasma.
Photonic Weyl degeneracies in magnetized plasma.
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DOI：
10.1038/ncomms12435
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发表时间：
2016-08-10
影响因子：
16.6
通讯作者：
Zhang S
中科院分区：
文献类型：
--
作者：
Gao W;Yang B;Lawrence M;Fang F;Béri B;Zhang S
外尔粒子是难以捉摸的相对论性费米子粒子，质量为零。虽然没有被发现作为基本粒子，但它们被发现出现在固态材料中，其中三维带发展出拓扑保护的点状交叉点，即所谓的外尔点。光子外尔点最近在具有复杂结构的三维光子晶体中实现。在这里，我们报告存在一种新型的等离子体Weyl点在自然存在的介质磁化等离子体，其中Weyl点出现纯粹的纵向等离子体模式和横向螺旋传播模式之间的交叉。这些光子Weyl点正好处于传统的封闭有限等距曲面的Weyl点和新提出的开放等距曲面的“II型”Weyl点之间的临界过渡处。等离子体外尔点引人注目的可观察特征包括在电磁反射中表现出的半k平面手性。我们的研究将外尔物理引入到均匀光子介质中，为实现新的拓扑光子器件铺平了道路。 外尔粒子是最近在固态材料中观察到的无质量相对论性费米子，其特征在于外尔点：能带结构中的拓扑保护交叉。在这里，作者证明了一种新型的等离子体Weyl点在磁化等离子体。
Weyl particles are elusive relativistic fermionic particles with vanishing mass. While not having been found as an elementary particle, they are found to emerge in solid-state materials where three-dimensional bands develop a topologically protected point-like crossing, a so-called Weyl point. Photonic Weyl points have been recently realised in three-dimensional photonic crystals with complex structures. Here we report the presence of a novel type of plasmonic Weyl points in a naturally existing medium—magnetized plasma, in which Weyl points arise as crossings between purely longitudinal plasma modes and transverse helical propagating modes. These photonic Weyl points are right at the critical transition between a Weyl point with the traditional closed finite equifrequency surfaces and the newly proposed ‘type II' Weyl points with open equifrequency surfaces. Striking observable features of plasmon Weyl points include a half k-plane chirality manifested in electromagnetic reflection. Our study introduces Weyl physics into homogeneous photonic media, which could pave way for realizing new topological photonic devices. Weyl particles are massless relativistic fermions recently observed in solid-state materials where they are characterized by Weyl points: topologically protected crossings in their band structure. Here, the authors demonstrate a novel type of plasmonic Weyl point in a magnetized plasma.