Electrical Control of Hybrid Monolayer Tungsten Disulfide–Plasmonic Nanoantenna Light–Matter States at Cryogenic and Room Temperatures

Abstract

Hybrid light–matter statespolaritonshave attracted considerable scientific interest recently, motivated by their potential for development of nonlinear and quantum optical schemes. To realize such states, monolayer transition metal dichalcogenides (TMDCs) have been widely employed as excitonic materials. In addition to neutral excitons, TMDCs host charged excitons, which enables active tuning of hybrid light–matter states by electrical means. Although several reports demonstrated charged exciton-polaritons in various systems, the full-range interaction control attainable at room temperature has not been realized. Here, we demonstrate electrically tunable charged exciton–plasmon polaritons in a hybrid tungsten disulfide (WS2) monolayer–plasmonic nanoantenna system. We show that electrical gating of monolayer WS2 allows tuning the oscillator strengths of neutral and charged excitons not only at cryogenic but also at room temperature, both at vacuum and atmospheric pressure. Such electrical control enables a full-range tunable switching from strong neutral exciton–plasmon coupling to strong charged exciton–plasmon coupling. Our experimental findings allow discussing beneficial and limiting factors of charged exciton–plasmon polaritons, as well as offer routes toward realization of charged polaritonic devices at ambient conditions.

Hybrid Plasmonics and Two-Dimensional Materials: Theory and Applications

“…129 Exploiting this property allows fabrication of tunable hybrid 2D-plasmonic devices. 113,130 By embedding an MoS 2 monolayer in a structure comprised by a gold mirror working as a back gate, SiO 2 spacer and a gold nanostrip array, Ni et al 131 were able to electrically control the emission of excitonplasmon polaritons.…”

Strong Dipole-Quadrupole-Exciton Coupling Realized in a Gold Nanorod Dimer Placed on a Two-Dimensional Material

“…More importantly, the binding energy of excitons in monolayer TMDCs is very large [ 23 ], implying that excitons can survive at room temperature. Thus far, the strong coupling between a TMDC monolayer and a photonic or plasmonic resonator has been successfully demonstrated, including optical microcavities [ 24 , 25 ], periodic nanostructures [ 26 , 27 ], single plasmonic nanoparticle antennas [ 28 , 29 , 30 , 31 , 32 , 33 , 34 ], and nanoparticle-on-film systems [ 35 , 36 , 37 , 38 , 39 , 40 ].…”

“…For a strongly coupled system consisting of a single nanoparticle and a TMDC monolayer, the typical Rabi splitting energy ranges from 80 to 120 meV [ 28 , 29 , 30 , 31 ]. Recently, strong coupling between excitons and the anapole mode formed by the interference of Mie resonances, which leads to a Rabi splitting of ~190 meV, has been observed in nanodisks made of multilayer WS 2 [ 41 ].…”

Surface‐enhanced Raman scattering probe for molecules strongly coupled with localized surface plasmon under electrochemical potential control

“…[ 29,30 ] As to the strong coupling, electrochemical potential control method would be also efficient to modulate the coupling strength because it can tune the electronic state of the system as well as the plasmonic property. [ 31–34 ] Our previous investigation about the electrochemical active tuning of the strong coupling has demonstrated the parabolic behavior change in the coupling strength depending on the electrochemical potential scan. [ 35 ] In addition, the electrochemical SERS measurements show the distinct dependence on the coupling strength.…”