Graduate students Kevin Miao, Chris Anderson, and Alexandre Bourassa monitor quantum experiments at the Pritzker School of Molecular Engineering

Scientists at the University of Chicago’s Pritzker School of Molecular Engineering have found a way to produce quantum states in ordinary, everyday electronics. By harnessing the properties of quantum mechanics without exotic materials or equipment, this raises the possibility that quantum information technologies can be created using current devices.

For decades, the computer industry has benefited from Moore’s law, which is a rule of thumb that predicts that the number of transistors on an integrated circuit will double about every two years. As this has held up, computers have gone from giant machines that were part of the buildings that housed them to tiny devices that can fit on a thumbnail, yet can outperform any supercomputer from previous generations.

It’s brought us the smartphone, the internet, and a whole range of applications that have changed our lives in what can only be called a revolution, but now Moore’s law is starting to break down. As miniaturized electronics approach their physical limits, it’s becoming harder and more expensive to produce more advanced chips.

It’s a problem that the average consumer won’t notice for at least a decade, but at the cutting edge of computer technology, it’s already having an effect. So scientists and engineers are seeking ways around Moore’s Law.

One of the most promising areas is quantum computing, which disposes of the traditional binary 1/0 architecture that computers have relied upon since the first digital computers were built, in favor of harnessing the peculiar, counterintuitive properties of quantum states, which allow information to be stored using quantum bits, or qubits, which can be 0, 1 or a superposition of both.

The problem is that present quantum computing technology relies on exotic materials like superconducting metals, levitated atoms, or diamonds. Standard electronics are seen as too crude to support delicate quantum states. But the Chicago team under David Awschalom, the Liew Family Professor in Molecular Engineering at UChicago and a pioneer in quantum technology, has found that by using silicon carbide it is possible to electrically control quantum states.

As an added bonus, the team discovered that the silicon carbide quantum states emit single photons of light in a wavelength near the telecommunications band. This means they could not only be used on fiberoptic networks, but also be combined with existing electronics to create new devices. The team was able to create what Awschalom describes as a “quantum FM radio” that is capable of transmitting quantum information over very long distances like a radio does sound.

The team also solved a problem that commonly plagues quantum technology – noise. The team was surprised to find that using a diode effectively freed the quantum signal of noise, and made it almost perfectly stable.

“This work brings us one step closer to the realization of systems capable of storing and distributing quantum information across the world’s fiber-optic networks,” says Awschalom. “Such quantum networks would bring about a novel class of technologies allowing for the creation of unhackable communication channels, the teleportation of single electron states and the realization of a quantum internet.”

The research is detailed in two papers published in Science and Science Advances, respectively.


Source: University of Chicago