Manchester announces quantum computing ‘breakthrough’

The university said that connecting qubits using supramolecular chemistry would generate several kinds of stable qubits that could be connected together into structures called “two-qubit gates”.

“We have shown that the chemistry is achievable for bringing together two-qubit gates - the molecules can be made, and the gates can be assembled," explained senior author Richard Winpenny, an inorganic chemist at the University of Manchester.

However, large assemblies of qubits that are stable enough to be applied to perform useful algorithms do not yet exist.

The researchers address this problem in their algorithm designs, which combine large molecules to create two qubits and a bridge between the units, called a quantum gate. These gates are held together through supramolecular chemistry, the university said.

According to the research, studies of the gates show that the quantum information stored in the individual qubits is stored long enough to allow manipulations of the information and hence algorithms. The time information that can be stored is called the coherence time.

Explaining, Winpenny said: “Say you’re in a pub and you’re trying to bring two pints of beer back to your friends without spilling it. But the pub is filled with customers who are singing, jumping around, and dancing. The coherence time is a measure of how far you can get the beer without spilling it.

“You want the bar to be very well behaved and very stationary so you can walk through the pub and get back to the table, just like we want the qubits to be stable long enough so we can store and manipulate information.”