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Introduction to Optical, Infrared, and Terahertz Frequency Bands
Published in Song Sun, Wei Tan, Su-Huai Wei, Emergent Micro- and Nanomaterials for Optical, Infrared, and Terahertz Applications, 2023
Song Sun, Wei Tan, Su-Huai Wei
The second type is the electronic terahertz source, which can be further divided into two sub-types: vacuum electronic and solid-state electronic sources. For the former type, travelling wave tube (e.g., backward wave oscillator, extended-interaction klystron oscillator) is commonly used to amplify electromagnetic signal from microwave to terahertz regimes. Other than that, vacuum particle accelerators (e.g., gyrotron, synchrotron, free electron laser) could also generate a broadband electromagnetic wave including terahertz band. The main advantage of vacuum electronic source is the high terahertz output power, but at a cost of bulky and expensive equipment. For the latter type, semiconductor diodes (e.g., Schottky-barrier diode) and transistors (e.g., BiCMOS, HEMT) are widely used for frequency multiplication up to the THz regime, and negative differential resistance devices (e.g., Gunn diode, resonant-tunneling diode) are employed as THz oscillators for direct THz wave generation. Up to date, the multiplier based on Schottky-barrier diode can operated at the frequencies up to ˜ 3 THz, while the oscillator based on resonant-tunneling diode can generate THz wave up to ˜ 2 THz. Recently, a novel solid-state terahertz source based on layered superconductor Bi2Sr2CaCu2O8 was developed. The advantage of solid-state electronic source relies on its high compactness and high integration level.
Nanoelectronics: Basic Concepts, Approaches, and Applications
Published in Rakesh K. Sindhu, Mansi Chitkara, Inderjeet Singh Sandhu, Nanotechnology, 2021
Balwinder Kaur, Radhika Marwaha, Subhash Chand, Balraj Saini
A resonant tunneling diode (RTD) is a diode in which electrons tunnel through some states that are in resonance. These diodes are operated by quantum mechanical tunneling, i.e., when a potential barrier is applied, electrons tunnel through certain energy levels. The tunneling of electrons is measured graphically via current–voltage characteristics. It was first proposed by Tus et al. [53]. The study of RTD is highly advantageous as circuit diagram is simple and negative differential resistance to yield to lower power consumption [54]. RTDs utilize microwave source (high frequency) in terahertz range [55]. RTDs have found their application in oscillators, optoelectronics, and detection of photons.
Graphene Nanodot Arrays
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
On the other hand, GNDs can be positioned (physically) separated from each other, but electrically connected via tunneling. Interestingly, when arranged in a 1D chain, these systems present a negative differential resistance due to a resonant tunneling occurring between the GNDs. The overall device constitutes a resonant tunneling diode, which can be used in terahertz frequency oscillators or memory devices (Al-Dirini et al., 2017).
Semiconductor full quantum hydrodynamic model with non-flat doping profile: (II) semi-classical limit
Published in Applicable Analysis, 2023
The full quantum hydrodynamic (FQHD) model is used for the simulation of semiconductor quantum devices, like the resonant tunneling diode [2–5], and reads as follows: Compared with the semi-classical full hydrodynamic (FHD) model, the new features of the FQHD model are the Bohm potential term in the momentum equation (1b) and dispersive velocity term in the energy equation (1c). Both of them are called quantum correction terms (or dispersive terms) and belong to the third-order derivative terms of the system (3).
Test Pattern Generator for MV-Based QCA Combinational Circuit Targeting MMC Fault Models
Published in IETE Journal of Research, 2022
Some of such paradigms are Single Electron Transistor (SET) [4], Resonant Tunneling Diode (RTD) [5] and Quantum-dot Cellular Automata (QCA) [6]. Among these, QCA has attracted more attention due to the features like low power dissipation, high device density and high switching speed. QCA is an array of cells in which each cell consists of four or six quantum dots. The basic devices in the QCA are MV, inverter, binary wire, fanout wire and L-shaped wire [7]. Each QCA synthesis circuit consists of a network of MVs and inverters.