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Ultrafast computing, such that would make computers function up to 100,000 times faster than conventional computers, is being made possible with the use of lasers. Scientists have developed a method of using ultrafast laser pulses to control the flow of electrons, instead of using voltage signals, as is used in traditional computing. This advancement represents a huge step towards light wave electronics, which could help catalyze progress in quantum computing. The use of the semiconductor graphene in this method has been instrumental, demonstrating how light can guide electrons through this material, resulting in super-fast computing.
Back in 2017, researchers at the University of Michigan established a method for successfully controlling the short peaks within laser pulses, peaks which last just a few femtoseconds. The team used a laser to shake the electrons in the superconductor graphene. A second laser was then used to control the ultrashort pulses that occurred as a result of movement of the electrons, and through doing this was able to control the direction of the current.
In traditional computers, electrons bump into each other as they move through a semiconductor, and this energy is released as heat. This new development of light wave electronics, on the other hand, means that electrons are much less likely to collide, making conductivity more efficient.
The team at Michigan have not been the only ones to successfully move electrons back and forth in solids using an oscillating electric field made up of ultrashort laser pulses. However, the recent advancement at Michigan has expanded on this advancement. They used terahertz radiation, which sits on the electromagnetic spectrum between microwaves and infrared light, to move electrons inside a semiconductor crystal. Their studies showed that with this method, electrons were able to move at a higher energy level, and through changing the laser’s orientation with respect to the crystal, the direction of movement of the electrons could be manipulated.
Up until this breakthrough, researchers had struggled to control the direction of the flow of electrons in metals, since metal reflects light, meaning that electrons moving through them cannot be impacted by these light waves. For this reason, the use of graphene has been instrumental.
Graphene has unique properties and, since its recent discovery in its stable form, it has generated a lot of research into its potential applications in all areas of science. The semi-metal is made of just one layer of carbon, making it thin and light enough so that light can pass through it, allowing electrons to be influenced by the pulses of light from the lasers. The second pulse of laser light is therefore able to permeate the graphene, changing the direction of the electron wave, accelerating its speed and even deflecting it.
With this research, scientists have made a significant step forward in creating light wave-controlled electronic systems. More studies need to be conducted in order to understand more about the nature of this relationship between electrons and light, in order to build small, light-controlled transistors.
In addition, the future could likely see this kind of technology aiding the development of quantum computing. Scientists theorize that the work that has been done with lasers and graphene may be useful for quantum computations using electrons in excited states as qubits.
Overall, what this research has opened is a way to create a new breed of computers that could process information at lightening speeds, the likes of which we have seen nothing of in modern computers. Through significantly increasing processing speeds, we will see the benefits in several sectors and time will tell what applications will come out of these ultrafast computers.
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