New transistor controlled by magnetic field

Nature : Transistors are the basic element of modern electronics. The devices serve as basic on/off logic gates controlled by a small amount of voltage. They are reliable, but maintaining the voltage consumes power. What’s more, because transistors must be hardwired, they require dedicated circuitry. A team of researchers led by Sungjung Joo of the Korea Institute of Science and Technology in Seoul, South Korea, has now created a magnetically controlled transistor that may overcome many of the drawbacks of traditional transistors. The team created a two-layer bridge out of the semiconductor indium antimonide. The top layer is filled with electrons and the lower layer is covered by positively charged “holes.” Depending on the direction of a magnetic field applied perpendicular to the bridge, electrons either flow through the upper layer or are forced into the holes in the lower layer. The ability to direct the magnetic field can be used to enable or disable sections of circuitry and thus “reprogram” the overall circuit to perform different functions. Although such transistors would be useful in any number of technologies, indium antimonide is difficult to incorporate into standard circuit manufacturing processes.