IBM has, for the first time, intertwined two quantum chips to work together. This approach is seen as the most promising path to making quantum computers useful.
North American technology giant IBM is betting on an unusual modular approach to building quantum computers and has succeeded connect two quantum chips to function as a single device.
This progress – in Nature this Wednesday – reinforces the viability of the company’s modular strategy for expanding the capacity of quantum computers.
Quantum computers have the potential to solve certain problems much faster than conventional computers. However, they face significant challenges, such as need to increase the size of computers and minimize errors.
Various research teams and companies explore different methods to overcome these difficulties. THE IBM opts for superconducting chips which can be manufactured by the same machines used for the hardware current computer.
As , one of the challenges of this technology is that the chip connectors are substantially larger than the qubits – which perform the calculations. Such a scenario forces qubits to be spaced further apart than transistors in conventional processors, limiting the number of qubits per chip. IBM’s solution involves chip interconnection.
Blake Johnsonfrom IBM, detailed to the magazine that the company’s strategy involves dividing the system into modules.
“It’s a game you win by dividing it into pieces. This is a core choice, an engineering choice that we made in terms of how we’re scaling up our systems. And there are scientific questions to be answered, as well as engineering questions to be answered about the consequences of that choice,” he explained.
Establishing communication between quantum chips is complex. Unlike conventional chips that use electrical signals, quantum computers rely on the phenomenon of .
To solve this problem, researchers developed a method that allows entangle two qubits and teleport one of them to another chip – creating a quantum connection between two devices, in a process that requires the mediation of a conventional computer.
To overcome this problem, scientists developed a method to entangle two qubits and teleport one of them to a second chip – creating a quantum connection between the two devices that must be mediated by a conventional computer.
IBM succeeded in connecting two of its Eagle quantum processing units (each with 127 qubits) to do a calculation that needed 142 qubits in total – more than would fit on either chip at once.
This modular approach is seen as the most promising path to turn prototypes into useful quantum computers. Until then, it was not clear that this method was viable.
“If there is no entanglement, this cannot work. But when you have an entangled resource, you can always use teleportation to swap a quantum channel for a classical channel – This is a very well-known trick. But obviously doing it in practice is different from doing it in theory,” he told New Scientist, Stefano Gogiosofrom the University of Oxford,
