Researchers at the University of Illinois at Chicago, in collaboration with their colleagues at the University of Hamburg in Germany, have imaged an exotic quantum particle—called a Majorana fermion—that can be used as a building block for future qubits and eventually the realization of quantum computers. Their findings are reported in the journal Science Advances.
More than 50 years ago, Gordon Moore, the former CEO of Intel, observed that the number of transistors on a computer chip doubles every 18 to 24 months. This trend, now known as Moore’s Law, has continued to the present day, leading to transistors that are only a few nanometers—one-billionth of a meter—in size. At this scale, the classical laws of physics, which form the basis on which our current computers work, cease to function, and they are replaced by the laws of quantum mechanics. Making transistors even smaller, which has been used in the past to increase computing speed and data storage, is, therefore, no longer possible.
Unless researchers can figure out how to use quantum mechanics as the new foundation for the next generation of computers.
This was the basic idea formulated in 1982 by Richard Feynman, one of the most influential theoretical physicists of the 20th century. Rather than using classical computer bits that store information encoded in zeros and ones, one would devise “quantum bits”—or qubits for short—that would utilize the laws of quantum mechanics to store any number between 0 and 1, thereby exponentially increasing computing speed and leading to the birth of quantum computers.
“Usually, when you drop your cell phone, it doesn’t erase the information on your phone,” said Dirk Morr, professor of physics at UIC and corresponding author on the paper. “That’s because the chips on which information is stored in bits of ones and zeros are fairly stable. It takes a lot of messing around to turn a one into a zero and vice versa. In quantum computers, however, because there is an infinite number of possible states for the qubit to be in, information can get lost much more easily.”