Fig 1 - uploaded by David Goldhaber-Gordon
Content may be subject to copyright.
Schematic cross section of a NMOS transistor. (a) The transistor shown in the schematic cross section is the basic building block of microcomputers. (b) When there is no voltage applied to the gate electrode, no current can flow through the semiconductor. (c) However, when voltage is applied to the gate electrode, the electrons (negative circles) segregate from the holes (positive circles) to form a “channel” which permits current (large white hatched arrows) to flow between the source and the drain.
Source publication
This paper provides an overview of research developments toward
nanometer-scale electronic switching devices for use in building
ultra-densely integrated electronic computers. Specifically, two classes
of alternatives to the field-effect transistor are considered: (1)
quantum-effect and single-electron solid-state devices and (2) molecular
electron...
Contexts in source publication
Context 1
... metal-oxide semiconductor FET (MOSFET) has been by far the most common type of transistor in modern microelectronic digital circuits, since Shockley's explana- tion of the device in 1952 [134], [135]. Properly designed MOSFET circuits use very little power and are economical to fabricate. As shown in Fig. 1, the field effect transistor has three terminals which are called the source, the drain, and the ...
Context 2
... of the MOSFET, whose voltage and associated electric field controls the flow of current from the source to the drain [27]. This is why the device is called a "field- effect" transistor. When the voltage on the gate is low, the region between source and drain contains few mobile negative charges, and very little current can flow. This is shown in Fig. 1(b). However, as illustrated in Fig. 1(c), increasing this voltage sufficiently attracts electrons to the region under the gate, opening the channel and allowing masses of electrons to flow from the source to the drain. This corresponds to a dramatic rise in current. This distinct change in conductivity makes the MOSFET a two-state device. ...
Context 3
... electric field controls the flow of current from the source to the drain [27]. This is why the device is called a "field- effect" transistor. When the voltage on the gate is low, the region between source and drain contains few mobile negative charges, and very little current can flow. This is shown in Fig. 1(b). However, as illustrated in Fig. 1(c), increasing this voltage sufficiently attracts electrons to the region under the gate, opening the channel and allowing masses of electrons to flow from the source to the drain. This corresponds to a dramatic rise in current. This distinct change in conductivity makes the MOSFET a two-state device. Since small changes of gate voltage ...
Context 4
... an actual experiment that approximates this design, Eigler et al. created a bistable atom switch with the aid of an STM. In their switch, a xenon atom transfers back and forth between the tip of an STM and a substrate [128], [160]. The location of this switching atom greatly affects the tunneling current that flows from the STM tip to the Fig. 10. Refined molecular switch, Type 1. The atom switch depicted in Fig. 9 might be refined by attaching the switching atom to a rotating molecular group. The orientation of the rotating group is to be controlled by a nearby gate molecule, to which a voltage can be applied for that ...
Context 5
... (b) Fig. 11. Refined molecular switch, Type 2. Switching atom might be attached to a "rotamer" that permits the atom to (a) be swung into position to turn the switch "on" by filling the gap in the atom wire, or (b) the switching atom is swung up out of the wire to turn "off" the current in the wire. Orientation of the rotamer is to be controlled ...
Context 6
... use the rotation of a molecular group to affect an electric current. We suggest that the atom relay discussed in the last section might be refined and made more reliable by attaching the switching atom to a rotating group, or "rotamer." This rotamer would be part of a larger molecule, perhaps affixed to the same surface as the atom wires. See Fig. 10 for a conceptual diagram of this arrangement (based upon a methyl-like group) and Takeda et al. [165] for a discussion of rotamers. The electric field of a nearby gate would force the switching atom to rotate in or out of the atom wire. When the switching atom is in the atom wire, the conductance of the atom wire is high-i.e., the ...
Context 7
... switch positions associated with the three groups attached to the rotamer. A more suitable molecule might be one that moves back and forth between only two distinct states. Cyclohexane, a simple example of this type of molecule, can bend into two different forms, commonly known as the "boat" and "chair" conformations [143], [163]. As shown in Fig. 11, a voltage on a nearby gate might force the cyclo- hexane switch into one of its two configurations, affecting the conductivity of a nearby atom wire. The cyclohexane- type molecule could link to a molecular framework while the remaining ring carbons would be replaced by groups tailored to use steric repulsions or chemical attractions ...
Context 8
... Molecular Shuttle Switch: A research group at the University of Miami-Coral Gables reports the synthesis of a "shuttle switch" [121]. This switch consists of two interlocking molecules of the type developed and refined in the pioneering work of the British chemist Stoddart [111], [113]. As seen in Fig. 12, the "shuttle" is a ring shaped molecule that encircles and slides (i.e., "shuttles") along a shaft-like chain molecule. Two large terminal groups at the end of the shaft prevent the shuttle ring from coming off the shaft. The shaft contains two other functional groups, a biphenol group and a benzidine group, which serve as natural ...
Similar publications
The radio-frequency single-electron transistor (rf-SET) possesses key requirements necessary for reading out a solid state quantum computer. This work explores the use of the rf-SET as a single-shot readout device in the presence of 1/f and telegraph charge noise. For a typical spectrum of 1/f noise we find that high fidelity, single-shot measureme...
Single electron electronics is now well developed, and allows the manipulation of electrons one-by-one as they tunnel on and off a nanoscale conducting island. In the past decade or so, there have been concerted efforts in several laboratories to construct single electron devices incorporating ferromagnetic components in order to introduce spin fun...
Citations
... Today, various quantum computing methods are used to study the properties of molecular nanoelectronic systems and open atomic subsystems (Dyck and Ratner 2015;Siddiqui 2020). Generally, molecular wires/ junctions and molecular switches are among the most important components of a molecular nanoelectronic circuit (Goldhaber-Gordon et al. 1997). Among these nanoelectronic devices, molecular switches have received a lot of attention due to their wide applications in turning ON and OFF electrical circuits and signal processing (Yang et al. 2008;Mendes et al. 2005;Sabzyan and Farmanzadeh 2007). ...
In this work, the switching mechanism of a molecular redox switch due to the application of an external electric field (along the X axis) was studied using density functional theory (DFT/TD-DFT), quantum theory of atom-in-molecule and Landauer theory. In this regard, some electronic, vibrational and optical properties of this molecular switch are calculated. In addition, the current–voltage (I–V) diagram, as well as Joule-like and Peltier-like ntermolecular phenomenological coefficients of this molecular switch, were calculated using Onsager linear Force-Flux law. When the electric field is applied along the X-axis (Ex) and its intensity increases to 40 × 10–4 a.u, the studied molecular switch is turned on. In addition, the results of this study showed that applying an external electric field has a significant effect on the optical properties of this designed molecular switch.
... While electrons possess efficient and reliable transmission/ response speeds, they lack characteristics inherent to biological structures such as self-healing capabilities etc., and struggle to adapt to extreme working environments with the influence of magnetic fields, high temperatures and high humidity [4]. Furthermore, electronic-based integrated circuits are approaching the limit of Moore's law based on von Neumann's computing architecture [5]. In contrast, ions could simultaneously carry rich information as charge carriers, for instance, Ca 2+ plays a pivotal role as a neurotransmitter release switch in neuronal conduction [6]. ...
The control of ion transport by responding to stimulus is a necessary condition for the existence of life. Bioinspired iontronics could enable anomalous ion dynamics in the nanoconfined spaces, creating many efficient energy systems and neuromorphic in-sensor computing networks. Unlike traditional electronics based on von Neumann computing architecture, the Boolean logic computing based on the iontronics could avoid complex wiring with higher energy efficiency and programmable neuromorphic logic. Here, a systematic summary on the state of art in bioinspired iontronics is presented and the stimulus from chemical potentials, electric fields, light, heat, piezo and magnetic fields on ion dynamics are reviewed. Challenges and perspectives are also addressed in the aspects of iontronic integrated systems. It is believed that comprehensive investigations in bioinspired ionic control will accelerate the development on more efficient energy and information flow for the futuristic human-machine interface.
... We then adjust the weights by increasing B, C, and D individually until we obtain a new weight vector of (5,4,3,2), where all weights are distinct. After a few iterations, the weight assignment algorithm returns a common weight vector (7,6,4,2) satisfying all the inequalities in Figure 11. The weight summations in the greater side and lesser side of f (x 1 , . . . ...
Threshold Function (TF) is a subset of Boolean function that can be represented with a single linear threshold gate (LTG). In the research about threshold logic, the identification of TF is an important task that determines whether a given function is a TF or not. In this paper, we propose a sufficient and necessary condition for a function being a TF. With the proposed sufficient and necessary condition, we devise a TF identification algorithm. The experimental results show that the proposed approach saves 80% CPU time for identifying all the 8-input NP-class TFs as compared with the state-of-the-art. Furthermore, the LTGs corresponding to the identified TFs obtained by the proposed approach have smaller weights and threshold values than the state-of-the-art.
... Spaceships, spacesuits, and equipment required to explore planets could benefit from new materials paired with nanosensors and nanorobots. It's employed in Nanophotonics, (Goldhaber- Gordon, 1997& Whitesides, 2005 which is the study of light's behaviour at the nanoscale size and how nanometerscale objects interact with light. Surface plasmons, metal optics, near field optics and metamaterials are used to squeeze light down to the nanoscale scale. ...
... The electrical and optical properties of molecular-scale junctions have attracted considerable interest owing to their potential in nanoelectronic devices. 1,2 Numerous studies have been conducted to understand the correlations between charge transport and light irradiation and emission in molecular-scale junctions using scanning tunneling microscopes (STMs), solid-state nanogap junctions, [24][25][26][27][28][29][30][31][32][33] and others. [34][35][36][37][38][39] Although many molecules exhibit excellent optical properties controlled by molecular designs, it is challenging to utilize them in molecular-scale electronics. ...
Understanding the mechanisms of electrically induced light emission in nanoscale junctions is crucial in molecular-scale optoelectronics. In this study, we investigated the light emission from nanogap electrodes with an insulating and nonluminescent material (polystyrene). Electrically induced light emission was observed over a wide wavelength range of 400–600 nm. The threshold voltages for the light emission ranged from 3 to 15 V, depending on the device, indicating that the electric field induced at the nanogap, rather than the applied potential, is the driving force for the light emission. The intensity of the light emission varies exponentially with the current with an exponent higher than 1.6, and the light emission is driven by a thermally activated current. These characteristics are inconsistent with the mechanisms reported for solid-state nanogap devices. We conclude that light emission in the nanogap electrodes is attributed to nanoscale vacuum discharge with metal plasma. The light emission from this mechanism can conflict with the other mechanisms ever reported since it occurs at such low voltages. The results also suggest intrinsic instability in molecular-scale electronic devices based on nanogap electrodes because the vacuum discharge is accompanied by the plasticization of the electrode.
... Spaceships, spacesuits, and equipment required to explore planets could benefit from new materials paired with nanosensors and nanorobots. It's employed in Nanophotonics, (Goldhaber- Gordon, 1997& Whitesides, 2005 which is the study of light's behaviour at the nanoscale size and how nanometerscale objects interact with light. Surface plasmons, metal optics, near field optics and metamaterials are used to squeeze light down to the nanoscale scale. ...
The increase in the global population demands new technologies in energy consumption and environmental changes. The energy and environment are the crucial factors for the evolvement of the human life. The advent and recent trends in nanotechnology offers promising approach in fulfilling the demands of human life. Nanotechnology is an emerging branch of science and technology which acts as a key role in environmental monitoring and energy conversion, distribution, and storage. The applications of nanoscale materials and nanoparticles in energy and environment enhance and simplify
the process flow with cost-effectiveness as well as eco-friendly approach over the current conventional methods. The applications of nanotechnology are versatile in various domains such as bioremediation, waste management, green technology, environmental monitoring, emission control, electricity production and transmission loss, solar power, etc.
... Spaceships, spacesuits, and equipment required to explore planets could benefit from new materials paired with nanosensors and nanorobots. It's employed in Nanophotonics, (Goldhaber- Gordon, 1997& Whitesides, 2005 which is the study of light's behaviour at the nanoscale size and how nanometerscale objects interact with light. Surface plasmons, metal optics, near field optics and metamaterials are used to squeeze light down to the nanoscale scale. ...
The increase in the global population demands new technologies in energy consumption and environmental changes. The energy and environment are the crucial factors for the evolvement of the human life. The advent and recent trends in nanotechnology offers promising approach in fulfilling the demands of human life. Nanotechnology is an emerging branch of science and technology which acts as a key role in environmental monitoring and energy conversion, distribution, and storage. The applications of nanoscale materials and nanoparticles in energy and environment enhance and simplify
the process flow with cost-effectiveness as well as eco-friendly approach over the current conventional methods. The applications of nanotechnology are versatile in various domains such as bioremediation, waste management, green technology, environmental monitoring, emission control, electricity production and transmission loss, solar power, etc.
... Limitations associated with minimizing CMOS tools prompted scientists to look for alternatives to transistors and the construction of circuits. Several technologies have been proposed as alternative solutions [8,9]. Silicon on Insulator [10], Resonant Tunneling Tools [11,12], Double Electron Layer Tunneling Transistors (DELTTs) [13], and Schottky-barrier (SB) MOSFET [14], Single-electron Transistor [15], Carbon Nanotube Transistors [16], Quantum-Dot Cellular Automata [17], Neural Networks [18,19], and molecular logic tools [20,21], as well as a number of computational architectures have been proposed for their use [22]. ...
Today, with the continuation of the reduction of the dimensions of transistors, the thickness of the gate is so small that it causes the leakage currents of the transistors to be very high. This prevents the reduction of power consumption and the speed of transistors. Also, construction costs, especially the lithography process, have increased greatly. In the next decade or two, as this trend continues, transistors will be the same size as atoms, and the laws of quantum physics will explain the behavior of atoms and no longer apply classical laws. Quantum-dot cellular automata technology is the vision of a new path for advancement in nanoelectronics and the design of small-scale computational circuits. Ternary logic is a promising proposition for designing QCA-based logic circuits. In this paper, for the first time, Two proposed single-trit comparator circuits based on ternary quantum cellular automaton technology were introduced. The first circuit was designed using a diagram block structure and truth table with 140 cells and area \({0.108 \upmu\text{m}}^{2}\). Using a physical proof of energy between cells, the second proposed circuit with 24 cells and area \({0.011 \upmu\text{m}}^{2}\) was designed. To measure the accuracy of performance, the circuit was simulated in TQCAsim software. Quantum cells have superiority with the aim of reducing power consumption, occupied space, and dramatically increasing work frequency. Comparisons show that the designs presented have improved compared to the previous ones.
... With the rapid evolution in transistor and semiconductor technologies, the size of electronic devices has shrunk to micro and nanometer scales in recent periods. But with the inclusion of micro and nano-electronic cooling devices, rapid heat dissipation has become an inexorable issue owing to the limitations of space [1,2]. Overheating can lead to potential damage to the components of nano-electronic devices and degrade their performance [2]. ...
In this study, atomistic simulations have been conducted in order to illustrate the effects of gradient and patterned wetting configurations on nanoscale condensation over hybrid wetting surfaces. To pursue this objective, a three-phase argon-platinum atomistic system has been modeled, consisting of two solid surfaces and two different phases of argon atoms. Following the necessary equilibration of the atomistic system at 90 K, the temperatures of the upper and lower surfaces are maintained at 130 K and 90 K, respectively, to make them serve as evaporating and condensing surfaces. The wetting characteristic of the lower surface is kept unchanged in all of the cases to corroborate the uniform evaporating condition, while that of the condensing wall has been changed to follow two major classes, namely, gradient and patterned wetting profiles. Functionally gradient wetting (FGW) surfaces have been modeled utilizing the power-law function from the notion of functionally graded material (FGM), whereas patterned wetting surfaces are modeled by juxtaposing the regions of different wettability. The condensation characteristics of different surfaces are reported with important parameters such as nucleation rate, cluster growth and coalescence, thermal resistance at the solid-liquid interface, condensed fluid atoms, mass flux of the condensate, condensing wall heat flux, and surface tension profile. The simulation results have revealed that an increased proportion of hydrophilic atoms enhances the condensation heat transfer. In addition, FGW surfaces have been found to be better than patterned ones in terms of condensation heat transfer enhancement.
... With this reduction comes the challenge of higher I ON /I OFF ratios and faster switching rates, which are important characteristics for any nano-scale device. [1][2][3][4] Short-channels effects have been a major concern while scaling down the devices. [5][6][7][8] Several techniques have been suggested by researchers over time to decrease the effect of SCEs in MOSFET devices. ...
As technological trends impose device dimension limitations, exploring other devices apart from metal oxide semiconductor field effect transistor, due to short-channel effects, has become inevitable. Higher ION/IOFF ratios and faster switching rates are quintessential characteristics for nanoelectronics. A field effect diode (FED) is one such device that exhibits greater drive current and low leakages when compared to silicon on insulator technology. Also, the FED fabrication process is compatible with complimentrary metal oxide semiconductor technology. Recently, several approaches have been proposed to tackle the low OFF current problem in FED such as Modified—FED and Side—Contacted FED. The FED structure proposed here is also believed to exhibit lesser short-channel effects, smaller OFF-state current, and higher ON-state current than a regular FED structure. We have explored the possible effects of material variation and work function engineering in our structure. Comprehensive analysis of the proposed device has also been done on some figures of merit such as subthreshold slope, energy-delay product, intrinsic gate delay, etc. thereby making this device suitable for electrostatic-discharge protection. Our numerical investigation promises FED’s efficacy in future logic applications in the nanometre regime.
