New Circuit Design Promises Cheaper Computer Chips

Scientists of the Massachusetts Institute of Technology (MIT) have created a new circuit design that can greatly reduce the manufacturing costs of computer chips.

The researchers presented their findings in the journal Nano Letters.

Computer chips with superconducting circuits, or circuits with zero electrical resistance, are estimated to be 50 to 100 times as energy-efficient as today’s computer chips. Superconducting chips also promise greater processing power, with superconducting circuits that use so-called Josephson junctions already having been clocked at 770 gigahertz, or 500 times the speed of the chip that can be found in Apple’s iPhone 6.

Josephson-junction chips are however large and hard to make. Most problematic of all is that the minute electrical currents that Josephson-junction chips generate after computations are very hard to detect.

The new circuit design for computer chips created by the researchers at MIT probably won’t top the speeds of today’s computer chips just yet, but it could solve the problem of reading out the results of calculations performed with so called Josephson junctions.

MIT researchers Adam McCaughan, a graduate student in electrical engineering, and his advisor, professor of electrical engineering and computer science Karl Berggren call their newly designed device the nanocryotron, named after the cryotron, an experimental computing circuit developed in the 1950s by MIT professor Dudley Buck.

“The superconducting-electronics community has seen a lot of new devices come and go, without any development beyond basic characterization,” McCaughan says. “But in our paper, we have already applied our device to applications that will be highly relevant to future work in superconducting computing and quantum communications.”

The most promising application of the nanocryotron, or nTron, could be making calculations performed by Josephson junctions accessible to the outside world. In experiments, McCaughan demonstrated that currents even smaller than those that are generated by Josephson-junction devices were adequate to switch the nTron from a conductive to a nonconductive state, big enough to carry information to other devices on a computer motherboard.

“I think this is a great device,” says Oleg Mukhanov, chief technology officer of Hypres, a superconducting-electronics company whose products rely on Josephson junctions. “We are currently looking very seriously at the nTron for use in memory.”
“There are several attractions of this device,” Mukhanov says. “First, it’s very compact, because after all, it’s a nanowire. One of the problems with Josephson junctions is that they are big. If you compare them with CMOS transistors, they’re just physically bigger. The second is that Josephson junctions are two-terminal devices. Semiconductor transistors are three-terminal, and that’s a big advantage. Similarly, nTrons are three-terminal devices.”

Source: http://computerstories.net/new-circuit-design-promises-cheaper-computer-chips/