The team of quantum physicists made this discovery after seven years of studying the behavior of photons (wave light particles) to better understand the phenomenon known as atomic excitation. This is where photons absorbed by a material experience a time delay (also known as group delay) before leaving the material as a result of the interaction with the atoms within it.
To better understand this process, researchers developed an experiment to send photons through a cloud of ultracold atoms and observe atomic excitation, Turkish Independent reported.
YOU KNOW THAT NEGATIVE VALUES ARE IMPORTANT
Surprisingly, the transit time for some photons through the atoms ended before the excitation of the atom ended, giving a negative value and making the photons appear to leave before they entered. to the material.
“These results show that negative values of times such as group delay have more physical meaning than generally accepted,” said researchers from the University of Toronto in Canada.
The results were described in the study titled “Experimental evidence that a photon can spend negative time in an atomic cloud”, which is still awaiting peer review.
Experimental quantum physicist Ephraim Steinberg of the University of Toronto wrote in X:
It took a good while, but our experiment shows that photons can make atoms spend *negative* time in the ready excited state! Sounds crazy, I know.
Speaking to Scientific American, Josiah Sinclair from the University of Toronto said his team was “very surprised” by the results.
A negative time delay may seem paradoxical, but it does mean that if you build a ‘quantum’ clock to measure the time that atoms spend in an excited state, the hands of the clock will move backwards rather than forwards under certain conditions.
The findings have no practical implications for our understanding of time, but they raise questions from previous work on photons and optics, while also revealing the mysterious nature of the quantum realm.
2024-10-02 14:43:15
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