A controlled Superconductor
The switch that turns off and on to command the superconducting property of the new device is a trivial electric field. In practice, what has been done by Andrea Ankle and colleagues at the University of Geneva in the first superconducting transistors. The operation, represents a milestone of applied physics and paves the way for the development of a new generation of microchips - and therefore computers - much faster than at present.
To understand how and why the device is considered so promising it must be from another discovery, made last year by the same group of university research in Switzerland and published in Science. In one study, physicists have created a single crystal in which two metal oxides (strontium titanate and lanthanum aluminate) are separated. Between these two materials, researchers have found a layer of free electrons (electronic cloud) and 0.3 Kelvin - that is just above absolute zero - traveling without any resistance. At that temperature, the crystal becomes a superconductor.
Scientists have now discovered how to turn off and turn on the superconductivity of this crystal at will, or modules, simply by applying an electric field to the point of contact between the two oxides. The result is a version of superconductive field effect transistors (FET) devices known in applied physics, able to switch from one state to a semiconductor insulator, and basic digital information in electronics (the fact that the current can pass or not is used as a binary 1-0 to store information).
As the field effect transistors is a semiconductor, however, it always has resistance to the passage of current. This means that the speed at which you can get the electrons when the device is "on" is limited which means heat develops beyond a certain limit. This side effect is damaging the transistor.
A superconducting transistor, however, can pass electrons (and record information) much more quickly, as it does not oppose any resistance to the passage of current and, therefore, not heat. There remains the problem of extremely low temperatures required for superconductivity. A limit that research is a long time trying to overcome.
To understand how and why the device is considered so promising it must be from another discovery, made last year by the same group of university research in Switzerland and published in Science. In one study, physicists have created a single crystal in which two metal oxides (strontium titanate and lanthanum aluminate) are separated. Between these two materials, researchers have found a layer of free electrons (electronic cloud) and 0.3 Kelvin - that is just above absolute zero - traveling without any resistance. At that temperature, the crystal becomes a superconductor.
Scientists have now discovered how to turn off and turn on the superconductivity of this crystal at will, or modules, simply by applying an electric field to the point of contact between the two oxides. The result is a version of superconductive field effect transistors (FET) devices known in applied physics, able to switch from one state to a semiconductor insulator, and basic digital information in electronics (the fact that the current can pass or not is used as a binary 1-0 to store information).
As the field effect transistors is a semiconductor, however, it always has resistance to the passage of current. This means that the speed at which you can get the electrons when the device is "on" is limited which means heat develops beyond a certain limit. This side effect is damaging the transistor.
A superconducting transistor, however, can pass electrons (and record information) much more quickly, as it does not oppose any resistance to the passage of current and, therefore, not heat. There remains the problem of extremely low temperatures required for superconductivity. A limit that research is a long time trying to overcome.
A total time face of the conductive properties due to the presence of an electric field has already been described last April in another study appeared in the pages of Nature. In that case, even passed from one state to superconductivity. Noted, moreover, for the first time .
Another recent and important discovery at the University of Florida (USA) in the field of superconductivity shows, however, the existence of materials that retain their peculiarities even if subjected to a very high magnetic fields
Another recent and important discovery at the University of Florida (USA) in the field of superconductivity shows, however, the existence of materials that retain their peculiarities even if subjected to a very high magnetic fields
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