Quantum Bits Hold Data for 39 Minutes, Smash World Record [CORRECTION]
For the first time, researchers have been able to demonstrate that information can be stored in quantum state for 39 minutes at room temperature. This is a world record in quantum computing. The study could pave way for super-fast computers.
The experiment was conducted by Mike Thewalt of Simon Fraser University in Canada and colleagues.
Conventional computers store data in bits- 0s and 1s. In quantum computing, data is held in qubits (quantum bits), which can exist in superposition, meaning that they can be a 0 or a 1 and everything in-between simultaneously. Qubits are atoms, ions photons and electrons that are working together as a computer. Since, quantum computers aren't limited to 'either-or' state, they can outperform the fastest supercomputers by running millions of calculations at the same time.
But, quantum computers are notoriously fickle and "forget" the information quickly as their superposition is destroyed as soon as it is manipulated by external forces (us).
Previous record for memory in such a fragile quantum state was about two seconds. There is another unofficial record, reported by BBC, which stands at 25 seconds at room temperature, or three minutes under extremely cold conditions.
The record of 39 minutes at a balmy 25 degree Celsius shows that it might be possible to have quantum computers storing memory at room temperature.
In the present experiment, researchers used phosphorus held on a tiny piece of silicon. They then encoded information in the nuclei of phosphorous atoms. The nuclei of atoms have an innate property called 'spin' that can be manipulated to up, down or in-between positions.
The information was embedded in the nuclei at -269C (minus 452 degrees Fahrenheit), which is very close to absolute zero.
Researchers used magnetic field pulses to change the orientation of the spin to create superpositions. At very low temperatures, about 37 percent of the ions remained in their superposition state for about three hours. The same percentage of ions held their position even after the temperature was raised to 25°C. At room temperature, they survived for 39 minutes.
"Thirty-nine 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 2 million operations could be applied in the time it takes for the superposition to naturally decay by 1%. Having such robust, as well as long-lived, qubits could prove very helpful for anyone trying to build a quantum computer," said Stephanie Simmons of Oxford University's Department of Materials, an author of the paper, according to a news release.
There is plenty of work to be done before we have quantum computers though. In the present test, researchers used 10 billion phosphorous atoms and put them under the same quantum state. However, to perform calculations, these qubits would have to be placed under many different superpositions.
The study is published in the journal Science.
Check a video by Google and NASA's Quantum AI Lab.
Correction: A previous verson of this article published Nov. 15 incorrectly cited "Oxford University and colleagues" as the researchers for the study instead of Mike Thewalt of Simon Fraser University.