A fragile quantum memory state has been held stable at room temperature for a “world record” 39 minutes – overcoming a key barrier to ultrafast computers.
“Qubits” of information encoded in a silicon system persisted for almost 100 times longer than ever before.
Quantum systems are notoriously fickle to measure and manipulate, but if harnessed could transform computing.
The new benchmark was set by an international team led by Mike Thewalt of Simon Fraser University, Canada.
“This opens the possibility of truly long-term storage of quantum information at room temperature,” said Prof Thewalt, whose achievement is detailed in the journal Science.
In conventional computers, “bits” of data are stored as a string of 1s and 0s.
But in a quantum system, “qubits” are stored in a so-called “superposition state” in which they can be both 1s and 0 at the same time – enabling them to perform multiple calculations simultaneously.
The trouble with qubits is their instability – typical devices “forget” their memories in less than a second.
There is no Guinness Book of quantum records. But unofficially, the previous best for a solid state system was 25 seconds at room temperature, or three minutes under cryogenic conditions.
In this new experiment, scientists encoded information into the nuclei of phosphorus atoms held in a sliver of purified silicon.
Magnetic field pulses were used to tilt the spin of the nuclei and create superposition states – the qubits of memory.
The team prepared the sample at -269C, close to absolute zero – the lowest temperature possible…..
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