Coupled plasmon–phonon modes in monolayer MoS₂

Abstract

We present a theoretical study of the plasmon-phonon coupling in a suspended monolayer MoS 2 and a MoS 2 substrate system using a diagrammatic self-consistent field theory. The four coupled plasmon-phonon modes and the four plasmon-surface phonon modes are observed due to the spin-orbit and electron-optic phonon interactions. The two of coupled plasmonphonon and plasmon-surface phonon modes are optic-like and the other two are acoustic-like. The plasmon are strongly coupled with the optic-phonon in MoS 2 and the surface opticphonon in the substrates as the electron density or wave-vector increases. The strong plasmonphonon coupling shows that the optoelectronic properties of monolayer MoS 2 are evidently modulated by electron-phonon interactions. The hybrid plasmon-phonon polaritons can be achieved by strong light-mater interactions. This study is relevant to the application of MoS 2 as novel plasmonic and nanophotonic devices.

Acousto‐Plasmo‐Magnonics: Coupling Spin Waves with Hybridized Phonon‐Plasmon Waves in a 2D Artificial Magnonic Crystal Deposited on a Plasmonic Material

“…However, plasmons can hybridize with phonons and produce a vibrational (phonon) mode of several GHz frequency that is comparable to the frequencies of SWs in ferromagnetic media. [13][14][15][16] Ref. [14], specifically, dealt with a monolayer system (MoS 2 ) and showed that four modes are produced as a result of phonon-plasmon coupling in that system, two of which are optical in nature and two are acoustic.…”

“…[13][14][15][16] Ref. [14], specifically, dealt with a monolayer system (MoS 2 ) and showed that four modes are produced as a result of phonon-plasmon coupling in that system, two of which are optical in nature and two are acoustic. The latter have frequencies in the range of zero to optical phonon frequencies and hence span the range of GHz frequencies that are the frequencies of spin waves in our systems.…”

Screening induced crossover between phonon- and plasmon-mediated pairing in layered superconductors

“…These particular plasmonic properties have a non-trivial influence on superconductivity that is qualitatively different from phonon mediated mechanisms. Additionally, the low-energetic gapless plasmon allows for efficient hybridization between plasmons and longitudinal optical phonons [55]. Thus, in contrast to conventional 3D superconductors, in which plasmons have large gaps, a fully momentum-dependent and dynamical theory is required to accurately describe 2D superconductors in the presence of electron-phonon and electron-electron interactions [34,35,[37][38][39][56][57][58].…”