Multiple-valued Logic Applications Research Articles

Basic circuit element for the implementation of base-3 and base-4 algorithms realized by an asymmetric MgO-based double-barrier magnetic tunnel junction

We study the resistance states and spin dynamics in a Ag/Fe(8)/MgO(3)/Fe(8)/MgO(5)/Fe/Ag junction based on a first-principles scattering theory. Spin dynamics simulations show that up to four resistance states with noticeable difference can be achieved via manipulating the voltage bias scheme and the position of the reference magnetization. The study indicates possible multiple-valued logic applications in an asymmetric MgO-based double-barrier magnetic tunnel junction.

Robust fuzzy SRAM for accurate and ultra‐low‐power MVL and fuzzy logic applications

A fuzzy static RAM (SRAM) is proposed, which is applicable in fuzzy logic and many multiple-valued logic (MVL) applications. The new structure is basically an extension to the binary SRAM cell. Two cross-coupled voltage mirror circuits are used to be able to hold an arbitrary voltage value. The proposed design forms a robust and reliable structure, which is capable of operating with more than 95% accuracy in spite of imperfect fabrication of carbon nanotube FETs. Another exceptional advantage is its ultra-low-power consumption in MVL environments. It consumes 38.7 and 99% less static power compared with the SRAMs with regular ternary and quaternary components, respectively.

Multiple Valued Logic: Concepts and Representations

Abstract Multiple Valued Logic: Concepts and Representations begins with a survey of the use ofmultiple-valued logic in several modern application areas including electronic design automation algorithms and circuit design. The mathematical basis and concepts of various algebras and systems of multiple valued logic are provided including comparisons among various systems and examples of their application. The book also provides an examination of alternative representations of multiple-valued logic suitable for implementation as data structures in automated computer applications. Decision diagram structures for multiple valued applications are described in detail with particular emphasis on the recently developed quantum multiple valued decision diagram.Table of Contents: Multiple Valued Logic Applications / MVL Concepts and Algebra / Functional Representations / Reversible andQuantum Circuits / Quantum Multiple-Valued Decision Diagrams / Summary / Bibliography

Application of InGaP/GaAs/InGaAs step-compositional-emitter structures for multiple-route switch

In this paper, a functional InGaP/GaAs/InGaAs step-compositional-emitter heterojunction bipolar transistor (SCEBT) is demonstrated. The excellent transistor performance, including a high current gain and a low collector–emitter offset voltage, is achieved under normal operation mode. In particular, an interesting three-state S-shaped negative-differential-resistance (NDR) switch is observed under inverted operation mode at room temperature because of the reduction of base barrier height and discontinuous confinement effects for electrons in a InGaP/GaAs heterojunction and InGaAs quantum well, respectively. The three-terminal base-controlled NDR characteristics and multiple-valued logic applications are also investigated. Consequently, the transistor action and switching characteristics of the studied SCEBT are promising for signal amplifier and logic circuit applications.

A systematic study of MOCVD grown InP/InGaAIAs heterojunction bipolar transistors with anomalous switching behavior

A new S-shaped switch based on the InP/InGaAlAs material system has been successfully fabricated and demonstrated. Due to the avalanche multiplication and potential redistribution process, the interesting multiple-negative-differential-resistance (MNDR) is found under the inverted operation mode at room temperature. The three-terminal NDR characteristics are investigated under the applied base current I B . Moreover, the anomalous multiple-route and multiple-step current-voltage (I-V) characteristics at 77K are also observed. The switching behaviors demonstrate that the proposed structure is a good candidate for multiple-valued logic applications.

Multiple-route and multiple-state current-voltage characteristics of an InP/AlInGaAs switch for multiple-valued logic applications

A novel multiple-state switching device based on an InP/AlInGaAs heterojunction bipolar transistor (HBT) structure has been successfully fabricated and demonstrated. The common-emitter current gain up to 25 is obtained under the forward operation mode. However, the anomalous multiple-negative-differential-resistance (MNDR) phenomena controlled either by electrical or optical input signals are observed under the inverted operation mode. The studied device exhibits a single-route S-shaped NDR behavior in the dark and a distinct significant S-shaped MNDR phenomena by introducing an incident light source at room temperature. Moreover, the anomalous multiple-route and multiple-step current-voltage (I-V) characteristics are also observed at 77 K. The switching behaviors are attributed to the avalanche multiplication, barrier lowering effect and potential redistribution process. Experimental results show that the studied device provides a good potentiality for multiple-valued logic and optoelectronic switching system applications.

Switches with double carrier confinement structures for multiple-valued logic applications

Two switching devices with different double carrier confinement structures were fabricated. One is a GaAs switch with double InGaP barriers, another with double GaAs-InGaAs delta-doped (-doped) quantum wells. In the characteristics of the former, because of the two-step barrier lowering induced by the processes of the carrier charging to the injection junction and carrier confinement in wells, a double S-shaped negative differential resistance (NDR) phenomenon is observed after the onsets of successive avalanche multiplications. However, only a single NDR performance is obtained in the characteristics of the latter due to one-step barrier lowering, even though successive avalanche multiplications also occur in the device operation.

Novel multipeak current-voltage characteristics of series-connected negative differential resistance devices

Three-peak current-voltage (I-V) characteristics can be obtained from the combination of two series-connected negative differential resistance (NDR) devices under certain conditions. We discuss these constraint conditions and demonstrate their role in the design of multipeak I-V characteristics based on NDR devices in series. These phenomena will provide some useful concepts in the multipeak circuit design. Especially, these novel multipeak I-V characteristics can be applied to the multiple-valued logic applications with less devices compared to the traditional structure that stacks N identical devices to obtain N peaks in the I-V curve.

Multiple negative-differential-resistance (MNDR) phenomena of a metal-insulator-semiconductor-insulator-metal (MISIM)-like structure with step-compositioned In/sub x/Ga/sub 1-x/As quantum wells

In this paper, a new multiple negative-differential-resistance (MNDR) device based on a metal-insulator-semiconductor-insulator-metal (MISIM)-like structure with step-compositional In/sub x/Ga/sub 1-x/As quantum wells has been fabricated and demonstrated. The interesting MNDR phenomena are found in the current-voltage (I-V) characteristics of this device. At room temperature, the triple switching behaviours and quadruple stable operation states are obtained. In addition, the sixfold switching behaviors and a staircase-shaped I-V characteristic are observed at -105/spl deg/C. A sequential carrier accumulation at InGaAs subwells and the potential lowering process are used to qualitatively explain the interesting MNDR phenomena. From the experimental results, it is shown that the studied device has good potential in multiple-valued logic applications.

A novel InGaP/GaAs S-shaped negative-differential-resistance (NDR) switch for multiple-valued logic applications

In this paper, a novel InGaP/GaAs multiple S-shaped negative-differential-resistance (NDR) switch based on a heterostructure-emitter bipolar transistor (HEBT) structure is fabricated and demonstrated. An interesting multiple NDR phenomenon resulting from an avalanche multiplication and successive two-stage barrier lowering process is observed under the inverted operation mode. The three-terminal-controlled and temperature-dependent NDR characteristics are also investigated. In addition, a typical transistor performance is found under the normal operation mode. Consequently, owing to the presented different stable operation points and transistor action, the studied device shows a good potential for multiple-valued logic and analog amplification circuit applications.

A Novel Functional Logic Circuit Using Resonant-Tunneling Devices for Multiple-Valued Logic Applications

We have demonstrated a novel functional logic circuit using resonant-tunneling devices. By integrating six InGaAs-based resonant-tunneling diodes (RTDs) and one HEMT on an InP substrate, we achieved room-temperature operation of an analog-to-quaternary quantizer, or an inverter in 4-valued logic. The circuit is suitable for multiple-valued logic applications because it exhibits multiple thresholds as well as multilevel output using a simple circuit configuration.

Multiple-route current-voltage (I-V) characteristics of GaAs-InGaAs metal-insulator-semiconductor-like (MIS) structure for multiple-valued logic applications

A new GaAs-In/sub x/Ga/sub 1-x/As metal-insulator-semiconductor-like (MIS) device with the interesting dual-route and multiple-negative-differential-resistance (MNDR) current-voltage (I-V) characteristics has been fabricated and demonstrated. These performances are caused by the successive barrier lowering and potential redistribution effect. A novel multiple-route I-V characteristic is obtained in the studied device at low temperature (-130/spl deg/C). This performance is different from the previously reported NDR switching device and has not yet been found in other devices. The interesting property of the studied structure provides a promising candidate for switching device applications.

A novel amorphous silicon doping superlattice device with double switching characteristics for multiple-valued logic applications

An amorphous silicon doping superlattice device with different period lengths is developed, providing a double switching characteristic that has been demonstrated to yield multiple stable states for multiple-valued logic applications. Unlike those of conventional switching devices, the switching characteristics of the present device are caused by avalanche multiplication and a barrier-lowering effect. A tristate memory cell using this device is proposed and discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A silicon double switching inversion-controlled switch for multiple-valued logic applications

A device with the structure of metal/thin insulator/crystalline silicon (n/sup +/-p)/thin insulator/metal (MISSIM) has been demonstrated to possess a double switching characteristics, which is expected to generate multiple stable states easier than the conventional resonant tunneling devices with multiple negative resistance for multiple-valued logic applications. Based on current-voltage measurements with or without light irradiation, and under the negative gate-biased condition, the operation mechanism of the MISSIM structure is proposed and illustrated in detail.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Resonant tunneling devices with multiple negative differential resistance and demonstration of a three-state memory cell for multiple-valued logic applications

A new resonant-tunneling (RT) functional device with two peaks in the current-voltage (I-V) characteristic has been demonstrated. Contrary to conventional RT devices, the peaks are obtained using a single resonance of the quantum well. The peak's separation is voltage tunable and the peak currents are nearly equal, which is important for a variety of device applications. Using a single device, a three-state memory cell has been implemented.

Resonant tunneling transistor with quantum well base and high-energy injection: A new negative differential resistance device

We propose a new negative conductance device consisting of a heterojunction bipolar transistor with a quantum well and a symmetric double barrier or a superlattice in the base region. The key difference compared to previously studied structures is that resonant tunneling is achieved by high-energy minority carrier injection into the quantum state rather than by application of an electric field. Thus this novel geometry maintains the crucial, structural symmetry of the double barrier, allowing unity transmission at all resonance peaks and higher peak-to-valley ratios and currents compared to conventional resonant tunneling structures. Both tunneling and ballistic injection in the base are considered. These new functional devices have significant potential for a variety of signal processing and multiple-valued logic applications and for the study of the physics of transport in superlattices.