Quantum world record smashed

From KurzweilAI:

A normally fragile quantum state has been shown to survive at room temperature for a world record 39 minutes, overcoming a key barrier towards building ultrafast quantum computers, the researchers say. An international team including Stephanie Simmons of Oxford University‘s Department of Materials report in this week’s Science a test performed by Mike Thewalt of Simon Fraser University, Canada and colleagues.

In the experiment, the team raised the temperature of a system — in which information is encoded in the nuclei of phosphorus atoms in silicon — from -269 °C to 25 °C and demonstrated that the superposition states survived at this balmy temperature for 39 minutes — outside of silicon, the previous record for such a state’s survival at room temperature was around two seconds. The team even found that they could manipulate the qubits as the temperature of the system rose, and that they were robust enough for this information to survive being “refrozen” (the optical technique used to read the qubits, which only works at very low temperatures). According to Simmons, an author of the paper, “39 minutes may not seem very long but as it only takes one-hundred-thousandth of a second to flip the nuclear spin of a phosphorus ion — the type of operation used to run quantum calculations — in theory over 20 million operations could be applied in the time it takes for the superposition to naturally decay by one percent. Having such robust, as well as long-lived, qubits could prove very helpful for anyone trying to build a quantum computer.” “This opens up the possibility of truly long-term coherent information storage at room temperature,” said Thewalt.

More here.