An international group of researchers, including a researcher from the Institute of Solid State Physics at the University of Tokyo, has made a groundbreaking discovery. They successfully demonstrated that a single molecule called fullerene is used as a transistor-like switch. The team achieved this by applying a precisely calibrated laser pulse that allowed them to predictably control the path of the incoming electron.
The switching provided by fullerene molecules can be significantly faster than switches used in microchips, with speed increases of three to six orders of magnitude depending on the laser pulses used. Using fullerene switches in a network could result in a computer with capabilities that far exceed those currently found in electronic transistors. Additionally, they have the potential to revolutionize microscopic imaging devices by providing unprecedented levels of resolution.
More than 70 years ago, physicists discovered that molecules emit electrons in the presence of electric fields and then certain wavelengths of light. The emission of electrons produced patterns that were intriguing but escaped explanation. But that has changed thanks to a new theoretical analysis whose results not only pave the way for new high-tech applications, but also improve our ability to study the physical world.
A simple analogy is how a fullerene key works like a train key. A pulse of light can change the path followed by an incoming electron, here represented by a circuit.
Project researcher Hirofumi Yanagisawa and his team theorized how electron emission from excited fullerene molecules should behave when exposed to certain types of laser light, and tested their predictions and got it right.
“What we can do here is control how the molecule directs the path of the incoming electron with a very short pulse of red laser light,” Yanagisawa said. Said. “Depending on the momentum of the light, the electron can either stay on its default course or be reoriented in a predictable way. It’s a bit like switching points on a railroad track or an electronic transistor, only much faster. We believe we can achieve a switching speed 1 million times faster than a conventional transistor.” And this could lead to real performance gains in computing. But just as importantly, if we could tune a laser to transition a fullerene molecule in multiple ways at once, it could be like having multiple microscopic transistors in a single molecule. can increase the complexity of the system without increasing its physical size.”
The fullerene molecule at the heart of the key is perhaps related to the slightly more famous carbon nanotube, but the fullerene is a sphere of carbon atoms rather than a tube. When placed on a metal point (mainly at the tip of a hairpin), fullerenes are predictably directed directly to electrons in a certain way. Fast laser pulses on the scale of femtosecond, quadrillionth of a second, or even attosecond, quintillionth of a second focus on fullerene molecules to cause the emission of electrons. This is the first time laser light has been used to control electron emission from a molecule in this way.
“This technique is similar to how a photoelectron emission microscope creates an image,” Yanagisawa said. Said. “However, at best they can achieve a resolution of about 10 nanometers, or ten billionths of a meter. Our Fullerene switch makes this better and provides a resolution of about 300 picometers, or three hundred trillionths of a meter.”
In principle, only a small network of fullerene switches would be needed to perform computational tasks potentially much faster than conventional chips, since several ultrafast electronic switches can be combined into a single molecule. However, there are several hurdles to overcome, such as how to miniaturize the laser component that will be required to build this new type of integrated circuit. Therefore, many years may pass before we see a smartphone based on the fullerene switch.
Source: Port Altele
