DELICATE quantum bits have been stored in single atoms, a feat
that could make accessing memory in quantum computersmore
convenient. Unlike classical bits, which can store only a 0 or
1, qubits can be in a superposition of the two states at once.
Two or more can also be "entangled" and remain linked across
great distances. Both properties vastly enhance the power of
quantum computers compared with normal ones. But while a qubit
can be encoded in the polarisation of a photon, which can
transport qubits efficiently, a good method for storing qubits
and reading them out later has eluded us. Patterns created in
ensembles of atoms can do the trick, but the information from
one qubit is spread over many atoms so accessing the qubit is
cumbersome. So Gerhard Rempe of the ... To continue reading this
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