Nonreciprocal and collimated surface plasmons in drift-biased graphene metasurfaces
Nonreciprocal and collimated surface plasmons in drift-biased graphene metasurfaces
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DOI：
10.1103/physrevb.100.081410
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发表时间：
2019-08-26
影响因子：
3.7
通讯作者：
Gomez-Diaz, J. S.
中科院分区：
文献类型：
--
作者：
Correas-Serrano, D.;Gomez-Diaz, J. S.
我们探索了在漂移偏置石墨烯基超表面中传播的表面等离子激元的不寻常的非互反和无衍射特性。我们表明，在石墨烯薄片上施加漂移电流会导致极不对称的平面内模态色散，从太赫兹到红外频率，与低损耗（高损耗和超高约束）的等离子体沿着（逆）偏压行进有关。引人注目的是，石墨烯固有的非局部响应阻止了真正的单向波传播，这是一种塑造表面能量流动的机制。我们还发现，高度定向的双曲等离子体激元完全不受后向散射的影响，在纳米结构石墨烯中沿漂移方向斜传播。最后，我们讨论了如何利用自旋轨道相互作用在这个平台上沿单一方向有效地发射准直等离子体，同时保持巨大的非互反响应。我们的发现提供了一个范例，激发，准直，引导和处理表面等离子体在宽频带。
We explore the unusual nonreciprocal and diffractionless properties of surface plasmon polaritons propagating in drift-biased graphene-based metasurfaces. We show that applying a drift current on a graphene sheet leads to extremely asymmetric in-plane modal dispersions, from terahertz to infrared frequencies, associated with plasmons with low loss (high loss and ultrahigh confinement) traveling along (against) the bias. Strikingly, truly unidirectional wave propagation is prevented by the intrinsic nonlocal response of a graphene, a mechanism that shapes the energy flow over the surface. We also show that highly directive hyperbolic plasmons completely immune to backscattering propagate obliquely along the drift in nanostructured graphene. Finally, we discuss how spin-orbit interactions can be exploited in this platform to efficiently launch collimated plasmons along a single direction while maintaining giant nonreciprocal responses. Our findings offer a paradigm to excite, collimate, steer, and process surface plasmons over a broad frequency band.