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Atomic switches are nanoionic devices that control the diffusion of metal cations and their reduction/oxidation processes in the switching operation to form/annihilate a metal atomic bridge, which is a conductive path between two electrodes in the on-state. In contrast to conventional semiconductor devices, atomic switches can provide a highly conductive channel even if their size is of nanometer order. In addition to their small size and low on-resistance, their nonvolatility has enabled the development of new types of programmable devices, which may achieve all the required functions on a single chip. Three-terminal atomic switches have also been developed, in which the formation and annihilation of a metal atomic bridge between a source electrode and a drain electrode are controlled by a third (gate) electrode. Three-terminal atomic switches are expected to enhance the development of new types of logic circuits, such as nonvolatile logic. The recent development of atomic switches that use a metal oxide as the ionic conductive material has enabled the integration of atomic switches with complementary metal-oxide-semiconductor (CMOS) devices, which will facilitate the commercialization of atomic switches. The novel characteristics of atomic switches, such as their learning and photosensing abilities, are also introduced in the latter part of this review. [ABSTRACT FROM AUTHOR]

The surface potential imaging of nanoscale domains engineered on near-stoichiometric LiNbO3 (SLN) crystals was investigated using Kelvin probe-based, electrostatic force microscopy. The surface potential image reflected in the domain structure was clearly obtained using heat treatment in vacuum due to the decreases in spontaneous polarization and screening charge adsorption. In-vacuum observation revealed that the surface potential contrast and polarity of nanoscale engineered domains can be repeatedly changed by switching the temperature between 298 and 393 K, demonstrating the controllability of the spontaneous polarization distribution in SLN crystals. [ABSTRACT FROM AUTHOR]

We propose a three-terminal nanometer metal switch that utilizes a solid electrolyte where a nanoscale metal filament is stretched and retracted. Its operating principle is based on electrochemical reaction and ion migration in the electrolyte. The fabricated device is composed of a solid electrolyte layer (CuS), a gate (Cu), a source (Cu), and a drain (Pt). After the Cu filament is formed between the source and the drain by applying the drain voltage, repeatable on/off switching in the drain current is obtained by controlling the gate voltage. The on/off current ratio can be as high as 10, and the programmable cycle is around 50. Each state can be kept for up to 40 days. Since the gate is separated from the current path, the switching current can be reduced to 10 μA, which is two orders of magnitude smaller than that of a two-terminal switch. In this paper, we present the operating principle and electrical characteristics of the three-terminal switches, and discuss how suitable they are for reconfigurable circuits. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(4): 55-61, 2011; Published online in Wiley Online Library (). DOI 10.1002/ecj.10214 [ABSTRACT FROM AUTHOR]

We have investigated solid electrolyte switches that utilize electrochemical reactions (deposition and dissolution) of metallic ions. The switch turns off or on when a metallic bridge electrochemically forms or dissolves in the solid electrolyte. Each state is nonvolatile and the switching is repeatable up to 105 cycles. The promising application is a programmable switch in a field programmable logic because of its small size (<30 nm) and low ON resistance (<100Ω). This paper discusses the electrical characteristics, operation principle, and applications of the solid electrolyte switch. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(1): 68–73, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20542 [ABSTRACT FROM AUTHOR]