Enhanced magnetochiral effects at microwave frequencies by a single metamolecule
Enhanced magnetochiral effects at microwave frequencies by a single metamolecule
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DOI：
10.1103/physrevb.95.085402
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发表时间：
2017-02
影响因子：
3.7
通讯作者：
S. Tomita;H. Kurosawa;K. Sawada;T. Ueda
中科院分区：
文献类型：
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作者：
S. Tomita;H. Kurosawa;K. Sawada;T. Ueda
实验和数值研究了室温直流磁场下单个超分子的磁手性效应对X波段微波的定向双折射。测量了波导中由铜手性结构和铁氧体圆柱体组成的单元分子从上到下的相位和振幅传输系数，即${S}_{21}$和${S}_{12}$的S参数。通过施加直流磁场，我们观察到${S}_{21}$和${S}_{12}$之间存在差异，这是同时出现空间反转和时间反转对称性破缺的MCh效应。基于有限元法的数值计算较好地再现了MCh效应的实验结果。利用铁氧体圆柱体的磁共振可以增强MCh效应。值得注意的是，数值计算预测，磁共振与特定的共振结构光学活性相互作用，极大地增强了MCh效应，导致了巨大的MCh效应。本研究中观察到的巨大MCh效应源于超分子中法诺共振引起的单向透明。
We have experimentally and numerically studied the directional birefringence of $X$-band microwaves by magnetochiral (MCh) effects of a single metamolecule under dc magnetic fields at room temperature. Phase and amplitude transmission coefficients from top and bottom, i.e., $S$ parameters of ${S}_{21}$ and ${S}_{12}$, are measured for the single metamolecule consisting of a copper chiral structure and ferrite cylinder in a waveguide. By applying a dc magnetic field, we observe a difference between ${S}_{21}$ and ${S}_{12}$, which is an emergence of the MCh effects with simultaneous space-inversion and time-reversal symmetry breaking. Numerical calculation based on a finite element method reproduces well the experimental results of the MCh effects. The MCh effect can be enhanced by using the magnetic resonance of the ferrite cylinder. Notably, numerical calculation predicts that the MCh effect is extremely enhanced by interacting magnetic resonance with a specific resonant structural optical activity, leading to a giant MCh effect. The giant MCh effect observed in the present study originates from the one-way transparency caused by the Fano resonance in the metamolecule.