Terahertz Dynamics of Quantum-Confined Electrons in Carbon Nanomaterials
نویسندگان
چکیده
Low-dimensional carbon nanostructures, such as single-wall carbon nanotubes (SWCNTs) and graphene, offer new opportunities for terahertz science and technology. Being zero-gap systems with a linear, photon-like energy dispersion, metallic SWCNTs and graphene exhibit a variety of extraordinary properties. Their DC and linear electrical properties have been extensively studied in the last decade, but their unusual finite-frequency, nonlinear, and/or non-equilibrium properties are largely unexplored, although they are predicted to be useful for new terahertz device applications. Terahertz dynamic conductivity measurements allow us to probe the dynamics of such photon-like electrons, or massless Dirac fermions. Here, we use terahertz time-domain spectroscopy and Fourier transform infrared spectroscopy to investigate terahertz conductivities of one-dimensional and two-dimensional electrons, respectively, in films of highly aligned SWCNTs and gated largearea graphene. In SWCNTs, we observe extremely anisotropic terahertz conductivities, promising for terahertz polarizer applications. In graphene, we demonstrate that terahertz and infrared properties sensitively change with the Fermi energy, which can be controlled by electrical gating and thermal
منابع مشابه
Effects of on-center impurity on energy levels of low-lying states in concentric double quantum rings
In this paper, the electronic eigenstates and energy spectra of single and two-interacting electrons confined in a concentric double quantum rings with a perpendicular magnetic field in the presence of on-center donor and acceptor impurities are calculated using the exact diagonalization method. For a single electron case, the binding energy of on-center donor and acceptor impurities ar...
متن کاملAnalytical quantum current modeling in GNSFET
Carbon nanoscrolls (CNSs) belong to the same class of carbon-based nanomaterialsas carbon nanotubes. As a new category of quasi one dimensional material Graphene Nanoscroll (GNS) has captivated the researchers recently because of its exceptional electronic properties like having large carrier mobility. GNS shape has open edges and no caps unlike Single Wall Nanotubes (SWNTs) which are wou...
متن کاملTerahertz Linear and Nonlinear Dynamics in Confined Magnetoexcitons
We have probed the linear and nonlinear terahertz (THz) properties of magnetoexcitons in GaAs/AlGaAs quantum wells. By monitoring photoluminescence from the quantum wells that were simultaneously driven by THz fields, we have directly observed internal transitions of excitons. In the nonlinear, high-THz-excitation regime, we observed mixing of optical and THz radiation, which resulted in THz op...
متن کاملTime-Domain Terahertz Magneto-Spectroscopy of Semiconductors
The terahertz frequency range, 0.1-10 THz, is one of the richest frequency ranges in condensed matter spectroscopy. Many important excitations and dynamical phenomena occur in this range, including superconducting gaps, protein conformational modes, phonons, and plasmons, just to name a few. Spectroscopic studies in this region provide valuable insights into the quantum states and dynamics of c...
متن کاملTerahertz science and technology of carbon nanomaterials.
The diverse applications of terahertz (THz) radiation and its importance to fundamental science makes finding ways to generate, manipulate and detect THz radiation one of the key areas of modern applied physics. One approach is to utilize carbon nanomaterials, in particular, single-wall carbon nanotubes and graphene. Their novel optical and electronic properties offer much promise to the field ...
متن کامل