WPG-Controlled Quantum BDD Circuits with BDD Architecture on GaAs-Based Hexagonal Nanowire Network Structure

Hong-Quan Zhao,Seiya Kasai

doi:10.1155/2012/726860

Abstract

One-dimensional nanowire quantum devices and basic quantum logic AND and OR unit on hexagonal nanowire units controlled by wrap gate (WPG) were designed and fabricated on GaAs-based one-dimensional electron gas (1-DEG) regular nanowire network with hexagonal topology. These basic quantum logic units worked correctly at 35 K, and clear quantum conductance was achieved on the node device, logic AND circuit unit, and logic OR circuit unit. Binary-decision-diagram- (BDD-) based arithmetic logic unit (ALU) is realized on GaAs-based regular nanowire network with hexagonal topology by the same fabrication method as that of the quantum devices and basic circuits. This BDD-based ALU circuit worked correctly at room temperature. Since these quantum devices and circuits are basic units of the BDD ALU combinational circuit, the possibility of integrating these quantum devices and basic quantum circuits into the BDD-based quantum circuit with more complicated structures was discussed. We are prospecting the realization of quantum BDD combinational circuitries with very small of energy consumption and very high density of integration.

Highlights

One of the interesting issues for the next-generation LSI technology is how to utilize a variety of quantum devices, for their manipulation of individual electrons, dissipation of little power, and fabrication in sizes ranging to molecular scale
We demonstrate the correct operation of quantum device fabricated on the GaAs-based 1-dimensional electron gas (1-DEG) nanowire and characterized the quantum logic AND and OR units
Node devices are implemented by attaching a nanometer-scale Schottky wrap gate (WPG) on each exit branch in the suitable network node, as shown in Figure 2(a) [16]

Summary

Introduction

One of the interesting issues for the next-generation LSI technology is how to utilize a variety of quantum devices, for their manipulation of individual electrons, dissipation of little power, and fabrication in sizes ranging to molecular scale. There are lots of reports about individual single-electron devices (SET) that work at room temperatures Those fabrication processes do not allow wires to cross, and no voltage gain existed. A logic function is represented by a directed graph with hexagonal topology [9,10,11], and the logical structure is directly implemented on a semiconductor nanowire network having the same topology [10, 11] This technique makes it possible to simplify design, circuit layout, device structure, and fabrication process. It is noted that the BDD allows us to use quantum nanodevices such as quantum wire or single-electron transistors in small circuits [11, 15] these devices have been understood quite difficult to implement conventional logic gate architecture due to small gain, small current drivability, and fluctuation. From elemental device characteristics and the measured ALU operations, the possibility to operate it in low voltage or in the quantum transport regime is discussed for the future option

Experimental

G0 2 G0 1 G0 1

Experimental Results and Discussion

Conclusion