Anomalous plasmon modes of single-layer MoS2

The electronic plasmons of single layer MoS2 induced by different spin subbands owing to spin-orbit couplings (SOCs) are theoretically investigated. The study shows that two new and anomalous plasmonic modes can be achieved via inter-spin subband transitions around the Fermi level due to the SOCs. The plasmon modes are optic-like, which are very different from the plasmons reported recently in single-layer (SL) MoS2, and the other two-dimensional systems. The frequency of such plasmons ascends with the increasing of electron density or spin polarizability, and decreases with the increasing of wave vector. The promising plasmonic properties of SL MoS2 make it interesting for future applications in plasmonic and terahertz devices.