Surface plasmons at the Brillouin zone boundary of an oblique lattice
Surface plasmons at the Brillouin zone boundary of an oblique lattice
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DOI：
10.1063/1.4914479
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发表时间：
2015-03
影响因子：
4
通讯作者：
Thomas J. Constant;P. Vukusic;A. Hibbins;J. Sambles
中科院分区：
文献类型：
--
作者：
Thomas J. Constant;P. Vukusic;A. Hibbins;J. Sambles
在低对称性的周期系统中，波沿布里渊区（BZ）边界的轮廓沿着完全干涉的布拉格条件通常不满足。因此，带隙不一定出现在该边界处。这封信证明了这一点，实验上记录的等频率轮廓表面等离子体激元（SPP）支持的衍射光栅与下面的二维斜Bravias晶格。结果表明，这些轮廓不相交的BZ边界垂直，作为对称操作的晶格放置在这个边界上的表面波干涉没有条件。
In periodic systems of low-symmetry, the Bragg condition for the complete interference of waves along the contour of the Brillouin zone (BZ) boundary is not generally satisfied. As a result, band-gaps do not necessarily occur at this boundary. This letter demonstrates this experimentally by recording the iso-frequency contours for surface plasmon polaritons (SPPs) supported on a diffraction grating with an underlying 2D oblique Bravias lattice. It is shown that these contours do not intersect the BZ boundary perpendicularly, as the symmetry operations of the lattice place no conditions on the surface wave interference at this boundary.