Engineers at EPFL have developed a way for studying a number of qubits – the smallest unit of quantum knowledge – on the similar time. Their technique paves the way in which to a brand new era of much more highly effective quantum computer systems.
“IBM and Google presently have the world’s strongest quantum computer systems,” says Prof. Edoardo Charbon, head of the Superior Quantum Structure Laboratory (AQUA Lab) in EPFL’s Faculty of Engineering. “IBM has simply unveiled a 127-qubit machine, whereas Google’s is 53 qubits.” The scope for making quantum computer systems even quicker is restricted, nonetheless, because of an higher sure on the variety of qubits. However a group of engineers led by Charbon, in collaboration with researchers within the U.Okay., has simply developed a promising technique for breaking by means of this technological barrier. Their strategy can learn qubits extra effectively, which means extra of them could be packed into quantum processors. Their findings seem in Nature Electronics.
Biochemistry and cryptography
Quantum computer systems don’t work just like the computer systems we’re used to. As an alternative of getting a separate processor and reminiscence chip, the 2 are mixed right into a single unit generally known as a qubit. These computer systems use quantum properties reminiscent of superposition and entanglement to carry out difficult calculations that common computer systems may by no means do in an inexpensive timeframe. Potential purposes for quantum computer systems embody biochemistry, cryptography, and extra. The machines utilized by analysis teams in the present day have round a dozen qubits.
“Our problem now’s to interconnect extra qubits into quantum processors – we’re speaking a whole lot, even 1000’s – with the intention to increase the computer systems’ processing energy,” says Charbon.
The variety of qubits is presently restricted by the truth that there’s no know-how but out there that may learn all of the qubits quickly. “Complicating issues additional, qubits function at temperatures near absolute zero, or –273.15oC,” says Charbon. “That makes studying and controlling them even more durable. What engineers sometimes do is use machines at room temperature and management every qubit individually.”
“It’s an actual breakthrough”
Andrea Ruffino, a PhD scholar at Charbon’s lab, has developed a way enabling 9 qubits to be learn concurrently and successfully. What’s extra, his strategy might be scaled as much as bigger qubit matrices. “Our technique relies on utilizing time and frequency domains,” he explains. “The fundamental thought is to scale back the variety of connections by having three qubits work with a single bond.”
EPFL doesn’t have a quantum pc, however that didn’t cease Ruffino. He discovered a solution to emulate qubits and run experiments underneath almost the identical situations as these in a quantum pc. “I integrated quantum dots, that are nanometer-sized semiconductor particles, right into a transistor. That gave me one thing that works the identical as qubits,” says Ruffino.
He’s the primary PhD scholar within the AQUA Lab to review this subject for his thesis. “Andrea confirmed that his technique works with built-in circuits on common pc chips, and at temperatures approaching qubit ones,” says Charbon. “It’s an actual breakthrough that would result in methods of enormous qubit matrices built-in with the required electronics. The 2 kinds of know-how may work collectively merely, successfully and in a reproducible method.”
Reference: “A cryo-CMOS chip that integrates silicon quantum dots and multiplexed dispersive readout electronics” by Andrea Ruffino, Tsung-Yeh Yang, John Michniewicz, Yatao Peng, Edoardo Charbon and Miguel Fernando Gonzalez-Zalba, 27 December 2021, Nature Electronics.