相关论文: Gate tunable third-order nonlinear optical respons…
Third-harmonic generation (THG) is a key nonlinear optical process for ultrafast imaging, terahertz (THz) signal generation, and symmetry-sensitive probes, often dominating in centrosymmetric materials where lower-order responses vanish.…
The development of optical metamaterials has resulted in the demonstration of remarkable physical properties, including cloaking, optical magnetism, and negative refraction. The latter has attracted particular interest, mainly because of…
Realizing flexible strain sensor with high sensitivity and tunable gauge factor is a challenge. To meet this challenge, we report an ionic liquid gated three-dimensional graphene field effect strain sensor. The charge carrier concentration…
Pristine, undoped graphene has a constant absorption of 2.3 % across the visible to near-infrared (VIS-NIR) region of the electromagnetic spectrum. Under certain conditions, such as nanostructuring and intense gating, graphene can interact…
The chemical stability of graphene and other free-standing two-dimensional crystals means that they can be stacked in different combinations to produce a new class of functional materials, designed for specific device applications. Here we…
We investigate the electronic band structure of graphene on a series of two-dimensional magnetic transition-metal phosphorus trichalcogenide monolayers, MPX$_3$ with M={Mn,Fe,Ni,Co} and X={S,Se}, with first-principles calculations. A…
We have performed scanning gate microscopy (SGM) on graphene field effect transistors (GFET), using a biased metallic nanowire coated with a dielectric layer as a contact mode tip and local top gate. Electrical transport through graphene at…
In moir\'e graphene systems, electronic interactions lift spin and valley degeneracies, leading to symmetry-broken ground states. In helical trilayer graphene (HTG), we uncover a distinct interaction-driven mechanism in which the roles of…
Strong light-matter coupling within electromagnetic environments provides a promising path to modify and control chemical and physical processes. The origin of the enhancement of nonlinear optical processes such as second-harmonic and…
Graphene based THz modulators are promising due to the conical band structure and high carrier mobility of graphene. Here, we tune the Fermi level of graphene via electrical gating with the help of ionic liquid to control the THz…
The metal-graphene contact resistance is a technological bottleneck for the realization of viable graphene based electronics. We report a useful model to find the gate tunable components of this resistance determined by the sequential…
We theoretically and numerically demonstrate an actively tunable slow light in a hybrid metal-graphene metamaterial in the terahertz (THz) regime. In the unit cell, the near field coupling between the metallic elements including the bright…
We study topologically-protected four-wave mixing (FWM) interactions in a plasmonic metasurface consisting of a periodic array of nanoholes in a graphene sheet, which exhibits a wide topological bandgap at terahertz frequencies upon the…
We present a degenerate four-wave mixing experiment on a silicon nitride (SiN) waveguide covered with gated graphene. We observe strong dependencies on signal-pump detuning and Fermi energy, i.e. the optical nonlinearity is demonstrated to…
It is highly desirable to integrate graphene into existing semiconductor technology, where the combined system is thermodynamically stable yet maintain a Dirac cone at the Fermi level. Firstprinciples calculations reveal that a certain…
Graphene is an ideal material for integrated nonlinear optics thanks to its strong light-matter interaction and large nonlinear optical susceptibility. Graphene has been used in optical modulators, saturable absorbers, nonlinear frequency…
A Fano-like phonon resonance is observed in few-layer (~3) graphene at room temperature using infrared Fourier transform spectroscopy. This Fano resonance is the manifestation of a strong electron-phonon interaction between the discrete…
The existence of large nonlinear optical coefficients is one of the preconditions for using nonlinear optical materials in nonlinear optical devices. For a crystal, such large coefficients can be achieved by matching photon energies with…
We report a highly efficient tunable THz reflector in graphene. By applying a small gate voltage (up to 3 V), the reflectance of graphene is modulated from a minimum of 0.79% to a maximum of 33.4% using graphene/ionic liquid structures at…
We demonstrate that the effective third-order nonlinear susceptibility of a graphene sheet can be enhanced by more than two orders of magnitude by patterning it into a graphene metasurface. In addition, in order to gain deeper physical…