Atomic 'conveyor belt' boosts power of quantum computer

"In a study published in Nature on 15 September, physicists show that the system can continuously replace and replenish the individual atoms suspended in an array by laser beams called 'optical tweezers'. Physicists have used such arrays to create some of the largest quantum computers to date - a technique called neutral-atom quantum computing - but the approach is hampered by the fact that some of the atoms inevitably get lost while they perform quantum computations."

"In the Nature paper, a team of physicists led by Mikhail Lukin at Harvard University in Cambridge, Massachusetts, created a two-dimensional array of more than 3,000 rubidium atoms, each at 9 micrometres from its neighbours, inside a high-vacuum vessel. Just below that array, they suspended a gas of rubidium atoms that could serve as a reservoir. Using the same type of optical tweezers that keep the first array in place, the team scooped up more atoms one by one from the reservoir to create a second array in what they call the 'preparation zone'."

"So far, state-of-the-art results in quantum computing have typically been obtained by encoding information either in trapped ions or in superconducting circuits, the approach taken by companies such as Google and IBM. The neutral-atom technique is a relatively recent entrant to the race towards building useful quantum computers, but has begun to attract massive investment."

A conveyor-belt arrangement of atoms in orderly rows can continuously replace and replenish individual atoms using laser beams called optical tweezers. The approach addresses atom loss, a key limitation of neutral-atom quantum computing that reduces array fidelity during computations. A two-dimensional array of more than 3,000 rubidium atoms, spaced 9 micrometres apart inside a high-vacuum vessel, can be paired with a nearby reservoir of rubidium gas. Atoms can be scooped one by one from the reservoir into a preparation zone and translated so each new atom sits side-by-side with an atom in the primary array for controlled interaction. The method improves array maintenance and supports scaling of atom-based quantum processors.

Read at Nature