Thanks to the new manufacturing method, industrial production of atomic-scale transistors for quantum computers is now possible.
Transistors, which until recently it was impossible to imagine – from individual atoms or their clusters – have already become a reality. Such transistors will be used in the next generation of computers – quantum computing machines with huge capabilities, previously unattainable memory capacity and high power.
Production of atomic-scale transistors for quantum computers is now possible
Scientists have already created transistors from one atom, but everything stalled due to the inability to start their commercial production – the devices could be manufactured only on a unit scale, moreover, it worked only at subzero temperatures.
A team of specialists from the National Institute of Standards and Technology in the United States, together with other researchers, was able to develop new technology for creating single-atom transistors. Today it is the first development of single-electron transistors with the ability to control the geometry on an atomic scale. Scientific work published in the journal Nature.
Rise of Quantum computers
The development was based on an existing invention. Scientists synthesized a chip of silicon, on the surface of which was a layer of hydrogen atoms. After that, scientists removed hydrogen in specific places using a scanning tunnelling microscope – one of the varieties of a scanning probe microscope.
A new method of depositing layers in an atomic transistor makes it possible to obtain more accurate and stable devices of atomic scale. Image: Pixabay
The barrier function was assigned to the atoms remaining on the surface of the silicon chip. Next, the silicon chip was placed in a stream of phosphine. Phosphine was attached to the surface of the chip only locally – in those places where hydrogen was removed.
The next step was to heat the chip surface – hydrogen atoms began to move away from phosphine, and only phosphorus atoms remained on silicon. And finally, after additional processing, scientists received highly efficient atomic-scale transistors.
The next task of the development team is to prove that it is possible to create tunneling in a transistor. The authors of the work were able to demonstrate that they are able to control the speed of electrons when particles overcome a gap or an electric barrier in the created system. Speed regulation is contrary to the laws of classical physics, which believes that this is impossible due to the too low energy of the electrons. Quantum tunneling is especially important in nanoscale designs like atomic transistors, since the gaps in them are very small. The ability to control the speed of electrons from outside is a sign that the created device can find application not only as a transistor, but also act as a qubit in a quantum system. It is tunneling that affects the ability of miniature transistors to create quantum entanglement.
Scientists were also able to demonstrate that the obtained transistors from single atoms can be manufactured on an industrial scale and, without waiting for the appearance of the next generation computers, can actually be used in existing devices.
