Physicists have implemented the first experimental demonstration of everlasting quantum coherence—the phenomenon that occurs when a quantum system exists in a superposition of two or more states at once. Typically, quantum coherence lasts for only a fraction of a second before decoherence destroys the effect due to interactions between the quantum system and its surrounding environment.
The collaboration of physicists, led by Gerardo Adesso at The University of Nottingham and with members from the UK, Brazil, Italy, and Germany, have published a paper on the demonstration of the extreme resilience of quantum coherence in a recent issue of Physical Review Letters.
“Quantum properties can be exploited for disruptive technologies but are typically very fragile,” Adesso told Phys.org. “Here we report an experiment which shows for the first time that quantum coherence in a large ensemble of nuclear spins can be naturally preserved (‘frozen’) under exposure to strong dephasing noise at room temperature, without external control, and for timescales as long as a second and beyond.”
That may help provide an underpinning to human brain states (changing one’s mind in a second).
The researchers predict that the surprising effect can occur in larger systems composed of any even number of qubits. Odd-numbered qubit systems do not exhibit the resilience because the specific initial conditions supporting the phenomenon cannot be met due to the different geometry of quantum states in such instances.
The researchers also showed that the mechanism appears to be universal, since it does not depend on the specific measure used to quantify the amount of coherence. The researchers expect that this trait will make the mechanism especially useful for future applications. More.
See also: Central galaxy black hole a quantum computer?
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