Tuning the Optical Properties of an MoSe${}_2$ Monolayer Using Nanoscale Plasmonic Antennas

Abstract

Nanoplasmonic systems combined with optically-active two-dimensional materials provide intriguing opportunities to explore and control light-matter interactions at extreme sub-wavelength lengthscales approaching the exciton Bohr radius. Here, we present room- and cryogenic-temperature investigations of light-matter interactions between an MoSe${}_2$ monolayer and individual lithographically defined gold dipole nanoantennas having sub-10 nm feed gaps. By progressively tuning the nanoantenna size, their dipolar resonance is tuned relative to the A-exciton transition in a proximal MoSe${}_2$ monolayer achieving a total tuning of $\sim 130\mathrm{meV}$. Differential reflectance measurements performed on $>100$ structures reveal an apparent avoided crossing between exciton and dipolar mode and an exciton-plasmon coupling constant of $g=55\mathrm{meV}$, representing $g/(\hslash {\omega }_X)\ge 3\%$ of the transition energy. This places our hybrid system in the intermediate-coupling regime where spectra exhibit a characteristic Fano-like shape, indicative of the interplay between pronounced light-matter coupling and significant damping. We also demonstrate active control of the optical response by varying the polarization of the excitation light to programmably suppress coupling to the dipole mode. We further study the emerging optical signatures of the monolayer localized at dipole nanoantennas at $10\mathrm{K}$. Our findings represent a key step towards realizing non-linear photonic devices based on 2D materials with potential for low-energy and ultrafast performance.

arXiv comment17 pages, 12 figures, https://pubs.acs.org/doi/10.1021/acs.nanolett.1c02676

References in corpus (41)

• Van der Waals heterostructures
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Fano resonances in nanoscale structures
• Observation of tightly bound trions in monolayer MoS2
• Exciton Binding Energy and Nonhydrogenic Rydberg Series in Monolayer WS2
• Excitons in atomically thin transition metal dichalcogenides
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Observation of Long-Lived Interlayer Excitons in Monolayer MoSe2-WSe2 Heterostructures
• Optical Generation of Excitonic Valley Coherence in Monolayer WSe2
• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Signatures of moiré-trapped valley excitons in MoSe${}_2$/WSe${}_2$ heterobilayers
• Large-scale quantum-emitter arrays in atomically thin semiconductors
• Deterministic strain-induced arrays of quantum emitters in a two-dimensional semiconductor
• Strong-coupling of WSe2 in ultra-compact plasmonic nanocavities at room temperature
• Strong exciton-plasmon coupling in MoS2 coupled with plasmonic lattice
• Gate-induced Superconductivity in atomically thin MoS2 crystals
• Exciton Diamagnetic Shifts and Valley Zeeman Effects in Monolayer WS${}_2$ and MoS${}_2$ to 65 Tesla
• Revealing exciton masses and dielectric properties of monolayer semiconductors with high magnetic fields
• Coherent Coupling of WS_2 Monolayers with Metallic Photonic Nanostructures at Room Temperature
• Fano resonance and spectrally modified photoluminescence enhancement in monolayer MoS2 integrated with plasmonic nanoantenna array
• Magneto-Optics of Exciton Rydberg States in a Monolayer Semiconductor
• Deterministic coupling of site-controlled quantum emitters in monolayer semiconductors to plasmonic nanocavities
• Electrically-driven optical antennas
• Charge-tuneable biexciton complexes in monolayer WSe${}_2$
• Revealing the Biexciton and Trion-exciton Complexes in BN Encapsulated WSe2
• Probing the influence of dielectric environment on excitons in monolayer WSe2: Insight from high magnetic fields
• Neutral and Charged Inter-Valley Biexcitons in Monolayer MoSe${}_2$
• Atomistic defect states as quantum emitters in monolayer MoS${}_2$
• Coulomb-bound four- and five-particle valleytronic states in an atomically-thin semiconductor
• Revealing Strong Plasmon-Exciton Coupling Between Nano-gap Resonators and Two-Dimensional Semiconductors at Ambient Conditions
• Enhanced light-matter interaction in an atomically thin semiconductor coupled with dielectric nano-antennas
• Light matter interaction in transition metal dichalcogenides and their heterostructures
• Discrete quantum dot like emitters in monolayer MoSe2: Spatial mapping, Magneto-optics and Charge tuning
• Single-crystalline gold nanodisks on WS${}_2$ mono- and multilayers: Strong coupling at room temperature
• Discrete Interactions between a few Interlayer Excitons Trapped at a MoSe${}_2$-WSe${}_2$ Heterointerface
• Scalable single-photon sources in atomically thin MoS2
• Coupling single photons from discrete quantum emitters in WSe${}_2$ to lithographically defined plasmonic slot-waveguides
• Radiative enhancement of single quantum emitters in WSe2 monolayers using site-controlled metallic nano-pillars
• Spontaneous emission from large quantum dots in nanostructures: exciton-photon interaction beyond the dipole approximation
• Controlling exciton many-body states by the electric-field effect in monolayer MoS${}_2$
• Optical properties and interparticle coupling of plasmonic bowtie nanoantennas on a semiconducting substrate

Cited by in corpus (3)

• Magneto-optical chirality in a coherently coupled exciton-plasmon system
• Electroluminescence as a probe of strong exciton-plasmon coupling in few-layer WSe2
• Probing the optical near-field interaction of Mie nanoresonators with atomically thin semiconductors