Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userObservation of Majorana Plasmon by Molecular Topological Superconductor and Its Topological SPASER
321
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Plasmons, quantized collective oscillations of electrons, have been observed in metals and semiconductors. Such massive electrons have been the basic ingredients of research in plasmonics and optical metamaterials.1 Also, Dirac plasmons have been observed in graphene, two-dimensional electron systems and topological insulators (TIs). A nontrivial Z2 topology of the bulk valence band leads to the emergence of massless Dirac fermions on the surface in TIs.2,3 Although Dirac plasmons can be formed through additional grating or patterning, their characteristics promise novel plasmonic metamaterials that are tunable in the terahertz and mid-infrared frequency ranges.4 Recently, the Majorana fermions have been verified through various kinds of topological superconductors(TSCs). In particular, the quantized and paired spin waves have been discovered in polyaromatic hydrocarbons(PAHs)5 and Majorana hinge and corner modes have been identified in the organic crystal of PAHs. Interestingly, regularity and periodicity can serve in the xy-plane of the crystal as the patterning of TSC resonators. Here, first we report experimental evidence of Majorana plasmonic excitations in a molecular topological superconductor (MTSC). It was prepared from MTSC resonators with different stacked numbers of HYLION-12. Distributing carriers into multiple MTSC resonators enhance the plasmonic resonance frequency and magnitude, which is different from the effects in a conventional semiconductor superlattice.6,7 The direct results of the unique carrier density scaling law of the resonance of massless Majorana fermions is demonstrated. Moreover, topological surface plasmon amplification by stimulated emission of radiation (SPASER) is also firstly created from the MTSC resonator. It has two mutually time-reversed chiral surface plasmon modes carrying the opposite topological charges.
rate research
Read More
Braiding operations are challenging to create topological quantum computers. It is unclear whether braiding operations can be executed with any materials. Although various calculations based on Majorana fermions show braiding possibilities, a braiding operation with a Majorana fermion has not yet been experimentally proven. Herein, braiding operations are demonstrated using a molecular topological superconductor (MTSC) that utilizes the topological properties intrinsic in molecules. The braiding operations were implemented by controlling two MTSC modules made by pelletizing crystals of 4,5,9,10-tetrakis(dodecyloxy)pyrene, which is proposed as the first MTSC material through n-MOSFETs. It shows the elements of topological quantum computers that can be demonstrated without an external magnetic field at room temperature.
We theoretically introduce a topological spaser, which consists of a hexagonal array of plasmonic metal nanoshells containing an achiral gain medium in their cores. Such a spaser can generate two mutually time-reversed chiral surface plasmon modes in the $mathbf K$- and $mathbf K^prime$-valleys, which carry the opposite topological charges, $pm1$, and are described by a two-dimensional $E^{prime}$ representation of the $D_{3h}$ point symmetry group. Due to the mode competition, this spaser exhibits a bistability: only one of these two modes generates, which is a spontaneous symmetry breaking. Such a spaser can be used for an ultrafast all-optical memory and information processing
Nanophononics is essential for the engineering of thermal transport in nanostructured electronic devices, it greatly facilitates the manipulation of mechanical resonators in the quantum regime, and could unveil a new route in quantum communications using phonons as carriers of information. Acoustic phonons also constitute a versatile platform for the study of fundamental wave dynamics, including Bloch oscillations, Wannier Stark ladders and other localization phenomena. Many of the phenomena studied in nanophononics were indeed inspired by their counterparts in optics and electronics. In these fields, the consideration of topological invariants to control wave dynamics has already had a great impact for the generation of robust confined states. Interestingly, the use of topological phases to engineer nanophononic devices remains an unexplored and promising field. Conversely, the use of acoustic phonons could constitute a rich platform to study topological states. Here, we introduce the concept of topological invariants to nanophononics and experimentally implement a nanophononic system supporting a robust topological interface state at 350 GHz. The state is constructed through band inversion, i.e. by concatenating two semiconductor superlattices with inverted spatial mode symmetries. The existence of this state is purely determined by the Zak phases of the constituent superlattices, i.e. that one-dimensional Berry phase. We experimentally evidenced the mode through Raman spectroscopy. The reported robust topological interface states could become part of nanophononic devices requiring resonant structures such as sensors or phonon lasers.
The rise of quantum science and technologies motivates photonics research to seek new platforms with strong light-matter interactions to facilitate quantum behaviors at moderate light intensities. One promising platform to reach such strong light-matter interacting regimes is offered by polaritonic metasurfaces, which represent ultrathin artificial media structured on nano-scale and designed to support polaritons - half-light half-matter quasiparticles. Topological polaritons, or topolaritons, offer an ideal platform in this context, with unique properties stemming from topological phases of light strongly coupled with matter. Here we explore polaritonic metasurfaces based on 2D transition metal dichalcogenides (TMDs) supporting in-plane polarized exciton resonances as a promising platform for topological polaritonics. We enable a spin-Hall topolaritonic phase by strongly coupling valley polarized in-plane excitons in a TMD monolayer with a suitably engineered all-dielectric topological photonic metasurface. We first show that the strong coupling between topological photonic bands supported by the metasurface and excitonic bands in MoSe2 yields an effective phase winding and transition to a topolaritonic spin-Hall state. We then experimentally realize this phenomenon and confirm the presence of one-way spin-polarized edge topolaritons. Combined with the valley polarization in a MoSe2 monolayer, the proposed system enables a new approach to engage the photonic angular momentum and valley degree of freedom in TMDs, offering a promising platform for photonic/solid-state interfaces for valleytronics and spintronics.
We study the effect of off-resonant plasmon modes on spaser threshold in nanoparticle-based spasers. We develop an analytical semiclassical model and derive spaser threshold condition accounting for gain coupling to higher-order plasmons. We show that such a coupling originates from inhomogeneity of gain distribution near the metal surface and leads to an upward shift of spaser frequency and population inversion threshold. This effect is similar, albeit significantly weaker, to quenching of plasmon-enhanced fluorescence near metal nanostructures due to excitation of off-resonant modes with wide spectral band. We also show that spaser quenching is suppressed for high gain concentrations and establish a simple criterion for quenching onset, which we support by numerical calculations for spherical geometry.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
