International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal.
Department of Physics, Center of Physics (CF-UM-UP), University of Minho, Campus of Gualtar, 4710-057, Braga, Portugal.
Nano Lett. 2023 May 24;23(10):4510-4515. doi: 10.1021/acs.nanolett.3c00907. Epub 2023 May 11.
Magnons and plasmons are different collective modes, involving the spin and charge degrees of freedom, respectively. Formation of hybrid plasmon-magnon polaritons in heterostructures of plasmonic and magnetic systems faces two challenges, the small interaction of the electromagnetic field of the plasmon with the spins, and the energy mismatch, as in most systems plasmons have energies orders of magnitude larger than those of magnons. We show that graphene plasmons form polaritons with the magnons of two-dimensional ferromagnetic insulators, placed up to to half a micrometer apart, with Rabi splittings in the range of 100 GHz (dramatically larger than cavity magnonics). This is facilitated both by the small energy of graphene plasmons and the cooperative super-radiant nature of the plasmon-magnon coupling afforded by phase matching. We show that the coupling can be modulated both electrically and mechanically, and we propose a ferromagnetic resonance experiment implemented with a two-dimensional ferromagnet driven by graphene plasmons.
磁振子和等离激元是两种不同的集体模式，分别涉及自旋和电荷自由度。在等离子体和磁性系统的异质结构中形成混合等离激元-磁振子极化激元面临两个挑战，即等离子体的电磁场与自旋的相互作用较小，以及能量不匹配，因为在大多数系统中，等离激元的能量比磁振子的能量大几个数量级。我们表明，石墨烯等离激元与放置在半微米之外的二维铁磁绝缘体的磁振子形成极化激元，拉比分裂在 100GHz 的范围内（比腔磁学大得多）。这得益于石墨烯等离激元的低能量和相位匹配提供的等离子体-磁振子耦合的协同超辐射性质。我们表明，这种耦合既可以通过电调制，也可以通过机械调制，我们提出了一个实验方案，即利用由石墨烯等离激元驱动的二维铁磁体来实现磁共振实验。
