Two ground-breaking advances have brought the quantum computing revolution one step closer to reality.
Using state-of-the-art laser techniques, two teams of scientists have manipulated more than 50 individual qubits – the fundamental unit of information in a quantum computer – to create record-breaking quantum simulators that are more powerful than anything that has come before.
Quantum simulators mimic the workings of true quantum computers – which are still in their infancy – enabling scientists to model the interactions between quantum particles, something which is very difficult to do for classical computers.
A greater understanding of these interactions will ultimately help researchers to build effective, large-scale quantum computers which may be able to solve certain problems that even the most powerful modern supercomputers can't handle.
Until now, quantum simulators have not been able to simulate more complex problems because they contained, at most, 45 qubits.
Qubits are the analogue of 'bits' in traditional computers. A bit can only have one of two values - 0 or 1 – whereas a qubit can exist in both states at the same time due to the quirks of quantum physics, meaning each one is able to perform more than one calculation simultaneously.
However, because of their complexity, qubits are incredibly hard to manufacture, and very difficult to manipulate when they are ready. A variety of different methods and materials have been used to try and build them.
The importance of the latest research is that it has demonstrated a level of control over the qubits that has never been seen before.
One of the teams involved scientists from the National Institute of Standards and Technology and the University of Maryland who made a quantum simulator consisting of 53 qubits – each made from individual atoms of the chemical element ytterbium, strung together in a chain.
The other team also involved researchers from Maryland as well as Harvard University. Their quantum simulator was very similar in design but consisted of 51 qubits that were each made from rubidium atoms instead of ytterbium.
The findings are published in the journal Nature.