Invented by Eiichi Goto

Eiichi Goto

Eiichi Goto was a Japanese computer scientist, the builder of one of the first general-purpose computers in Japan.-Biography:Goto was born in January 26, 1931 in Shibuya, Tokyo. After attending Seikei High School he went to Tokyo University, where he graduated in 1953...

 at the University of Tokyo

University of Tokyo

, abbreviated as , is a major research university located in Tokyo, Japan. The University has 10 faculties with a total of around 30,000 students, 2,100 of whom are foreign. Its five campuses are in Hongō, Komaba, Kashiwa, Shirokane and Nakano. It is considered to be the most prestigious university...

, the Quantum Flux Parametron (QFP) is an improvement over his earlier parametron

Parametron

Parametron is a logic circuit element invented by Eiichi Goto in 1954. The parametron is essentially a resonant circuit with a nonlinear reactive element which oscillates at half the driving frequency...

 based digital logic technology. Unlike its predecessor, QFP uses superconducting

Superconductivity

Superconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum...

 Josephson junctions on integrated circuits to improve speed and energy efficiency enormously. In some applications, the complexity of the cryogenic cooling system required is negligible compared to the potential speed gains. While his design makes use of quantum

Quantum mechanics

Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...

 principles, it is not a quantum computer

Quantum computer

A quantum computer is a device for computation that makes direct use of quantum mechanical phenomena, such as superposition and entanglement, to perform operations on data. Quantum computers are different from traditional computers based on transistors...

 technology, gaining speed only through higher clock

Clock signal

In electronics and especially synchronous digital circuits, a clock signal is a particular type of signal that oscillates between a high and a low state and is utilized like a metronome to coordinate actions of circuits...

 speeds. Apart from the speed advantage over traditional CMOS

CMOS

Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...

 integrated circuit

Integrated circuit

An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

 design is that parametrons can be operated with zero energy loss (no local increase in entropy

Entropy

Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...

), making reversible computing

Reversible computing

Reversible computing is a model of computing where the computational process to some extent is reversible, i.e., time-invertible. A necessary condition for reversibility of a computational model is that the transition function mapping states to their successors at a given later time should be...

 possible. Low energy use and heat generation is critical in supercomputer

Supercomputer

A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation.Supercomputers are used for highly calculation-intensive tasks such as problems including quantum physics, weather forecasting, climate research, molecular modeling A supercomputer is a...

 design, where thermal load per unit volume is has become one of the main limiting factors.

A related technology is the Rapid Single Flux Quantum

Rapid single flux quantum

In electronics, rapid single flux quantum is a digital electronics technology that relies on quantum effects in superconducting devices, namely Josephson junctions, to process digital signals. Josephson junctions are the active elements for RSFQ electronics, like transistors are the active...

digital logic.

External links

• Parametron, The History of Computing project
• Parametron, early computers, Information Processing Society of Japan