A major obstacle in the development of powerful quantum computers is the growing number of cables required to control a computer as the number of qubits increases. Researchers at Chalmers University of Technology in Sweden have now demonstrated that several qubits can share the same cable—without significantly increasing computation time. Their study is the most comprehensive of its kind and could become an important piece of the puzzle in developing quantum computers. These computers have the potential to revolutionize such areas as drug development and logistics.

The power of quantum computers lies in what are known as “qubits.” Unlike a conventional computer “bit,” which can have the value 1 or 0, a qubit can have the values 1 and 0 simultaneously—and all states in between, in any combination. This means a quantum computer with 20 qubits can simultaneously represent a combination of more than one million different states, resulting in enormous computational power.

“The global quantum technology race is in full swing, with tech giants currently in the lead with quantum computers based on more than 100 qubits. But to solve real-world societal challenges, quantum computers will need grow much further in size, with thousands or more well-functioning qubits,” says Anton Frisk Kockum, Associate Professor of Applied Quantum Physics at Chalmers University of Technology. At Chalmers, researchers have been developing Sweden’s largest quantum computer within the Wallenberg Centre for Quantum Technology.