相关论文: Negative terahertz conductivity in disordered grap…
We report on spectroscopy results from the mid- to far-infrared on wafer-scale graphene, grown either epitaxially on silicon carbide, or by chemical vapor deposition. The free carrier absorption (Drude peak) is simultaneously obtained with…
We experimentally observe the fast relaxation and relatively slow recombination dynamics of photogenerated electrons/holes in an epitaxial graphene-on-Si heterostructure under pumping with a 1550-nm, 80-fs pulsed fiber laser beam and…
We show that a strong infrared laser beam obliquely incident on graphene can experience a parametric instability with respect to decay into lower-frequency (idler) photons and THz surface plasmons. The instability is due to a strong…
The transmission across a graphene bilayer region is calculated for two different types of connections to monolayer leads. A transfer matrix algorithm based on a tight binding model is developed to obtain the ballistic transmission beyond…
The paper discusses the chiral tunnelling of charge carriers through double barrier structure in twisted graphene bilayer. The theoretical analysis investigates the transmission probability for various system parameters under both symmetric…
Sub-wavelength graphene structures support localized plasmonic resonances in the terahertz and mid-infrared spectral regimes. The strong field confinement at the resonant frequency is predicted to significantly enhance the light-graphene…
An interlayer distance modulation in twisted bilayer graphene is reported. This is achieved by an in-situ annealing technique. The transformation of systematic vacuum and hydrogen annealing effects in twisted bilayer CVD graphene on SiO2…
The efficient modulation and control of ultrafast signals on-chip is of central importance in terahertz (THz) communications and a promising route toward sub-diffraction limit THz spectroscopy. Two-dimensional (2D) materials may provide a…
We propose use of disorder to produce a field effect transistor (FET) in biased bilayer and trilayer graphene. Modulation of the bias voltage can produce large variations in the conductance when the disorder's effects are confined to only…
Photon-assisted charge transport through a double barrier laser structure, separated by a region assisted by a magnetic field, is studied. Employing Floquet theory and matrix formalism, the transmission probabilities for the central band…
Twisted bilayer graphene (TBG) represents a highly tunable, strongly correlated electron system owed to its unique flat electronic bands. However, understanding the single-particle band structure alone has been challenging due to complex…
Twisted Bilayer Graphene at the magic twist angle features flat energy bands, which lead to superconductivity and strong correlation physics. These unique properties are typically limited to a narrow range of twist angles around the magic…
Terahertz (THz) fields are widely applied for sensing, communication and quality control. In future applications, they could be efficiently confined, enhanced and manipulated - well below the classical diffraction limit - through the…
We propose and evaluate the vertical cascade terahertz and infrared photodetectors based on multiple-graphene-layer (GL) structures with thin tunnel barrier layers (made of tungsten disulfide or related materials). The photodetector…
Twisted bilayer graphene (TBG) exhibits extremely low Fermi velocities for electrons, with the speed of sound surpassing the Fermi velocity. This regime enables the use of TBG for amplifying vibrational waves of the lattice through…
Electrical control of amplitude and phase of terahertz radiation (THz) is the key technological challenge for high resolution and noninvasive THz imaging. The lack of an active materials and devices hinders the realization of these imaging…
Using synchronized near-infrared (NIR) and terahertz (THz) lasers, we have performed picosecond time-resolved THz spectroscopy of transient carriers in semiconductors. Specifically, we measured the temporal evolution of THz transmission and…
Bilayer graphene is a promising material for radio-frequency transistors because its energy gap might result in a better current saturation than the monolayer graphene. Because the great deal of interest in this technology, especially for…
The gap in bilayer graphene (BLG) can directly be controlled by a perpendicular electric field. By tuning the field through zero at a finite rate in neutral BLG, excited states are produced. Due to screening, the resulting dynamics is…
Electrically tuneable high mobility charges on graphene yield an efficient electro-optical platform to control and manipulate terahertz (THz) waves. Real-world applications require a multiplex THz device with efficient modulation over a…