Quantum states are extremely unstable, but have incredible capabilities. Einstein called the same state of quantum entanglement “terrible” and could not fully accept that entangled atoms could “feel” each other at different ends of the Universe. Such properties are invaluable for making ultra-sensitive measurements and even searching for new physics, but they are hampered by the extremely short coherence times that scientists in China have overcome.
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An article by researchers from the University of Science and Technology of China has appeared on the arXiv website, which states that the quantum states of atoms are retained for 23 minutes, which can be considered an absolute record. Typically, the coherence time does not exceed a few milliseconds, which is a multiple of the new achievement. The article has not yet been peer-reviewed and should be taken with caution. However, if other teams can repeat the experience of Chinese scientists, this will be a major breakthrough in the development of quantum technologies.
The experiment involved cooling 10,000 ytterbium atoms to a few thousandths of a degree above absolute zero, which were then trapped in the electromagnetic fields of laser radiation. Under these conditions, the quantum states of atoms could be controlled very precisely, and the researchers took advantage of this to put each atom into a superposition of the two states with the most widely different spins.
Precise tuning of lasers – optical traps – made it possible to keep atoms in a state of superposition for 1400 seconds or 23 minutes. This time will be enough to carry out experiments in quantum physics, for measurements with an error less than the quantum limit (this is the so-called quantum superiority in metrology), for quantum computer memory, and finally.