Electronic extreme: transistor operates with a single electron

Writing Site Innovation - 20/04/2011

An international research team, featuring Brazilian, has created a single electron transistor - or, rather, at most two electrons.The research is in a border area between traditional electronics and quantum computing.In theory, the single electron transistor could be useful both for creating ultra-dense memories, leading to miniaturization to another level, and function as a qubit for a quantum computer.Isle of electronsIn 2006, the team of Professor Jeremy Levy of the University of Pittsburgh, has created germanium quantum dots that were placed on a silicon substrate with a precision of 2 nm, were capable of confining single electrons.In 2009, the group created a universal platform for making electronic components with dimensions close to the atomic scale.Now they all ingredients together and created an island of electrons "measuring just 1.5 nanometers in diameter.The island becomes the center of the single electron transistor when it receives one or two residents - one or two electrons.The electrons are taken there by nanowires, which act as the electrodes of the transistor. The number of trapped electrons - which can only be zero, one or two - change the conduction properties of the device.This allows the component to function as an artificial atom, of great interest in the field of quantum computing.Electric sensor and forceElectrons tunneling from one wire to another over the island. The voltage on the third wire controls the conductive properties of the site, causing the electron to tunnel or not - hence its functioning as a transistorThe main advantage of single electron transistor is its extreme sensitivity to an electric charge, making it potentially an electric sensor with an unprecedented level of precision.The component is ferroelectric, meaning that it can function as a solid state memory that does not lose data in the absence of electricity.Ferroelectricity also makes the transistor sensitive to pressure at the nanoscale, making it potentially useful as a force sensor.Electronic extreme: transistor operates with a single electronElectrons tunneling from one wire to another across the island, which can function as a transistor, as an artificial atom or as a sensor of electrical charge or force. [Image: Cheng et al. / Nature Nanotechnology]Single electron transistorsScientists have already managed to build single electron transistors (see transistor is operating with a single electron transistor Created and powered by a single electron) and even a mechanical transistor controlled by a single electron.The field also includes a call atomotrônica atomic transistor, which forms a bridge between computation and quantum electronics.This research is distinguished by the material used - this is the first single electron transistor made entirely of oxides - and the manufacturing technique.But this fabrication technique is away from that with which traditional transistors are made in factories, scientists use the thin tip of a atomic force microscope to manipulate atoms at the interface between a crystal of strontium titanate film and an aluminate lanthanum.