Trio who proved quantum mechanics is really weird—and useful—honored

In a citation many physicists expected for decades, this year's Nobel Prize in physics honors three researchers who probed a weird quantum mechanical phenomenon calledentanglement, paving the way for the burgeoning fields of quantum communications and quantum computing.

Two of them, John Clauser of J.F. Clauser & ASSOCIATES and Alain Aspect of the University of Paris-Saclay, proved quantum entanglement. The University of Vienna's Anton Zeilinger showed how entangled particles could be used to communicate. The three received the same amount of money.

Adrian Kent is a quantum physicist at Cambridge. It's time for these giants to be recognized. The prize is a beautiful one according to Ronald Hanson, a quantum physicist. He says that the work of the Laureates has opened up the field of quantum information science.

Einstein was unhappy with the nature of quantum mechanics when he was younger. The property of an electron depends on how it is measured, according to quantum theory. Measure the electron's position and it will change. It can either have a definite position or not. Einstein believed that a particle's position and momentum should not be measured. Hidden variables predetermine the values.

The idea was proposed by John Bell in 1964. Even though the state of each individual particle is unknown, their two states are completely correlated. According to quantum mechanics, a photon can be either vertically or horizontally divided. Even though the polarization of each photon is uncertain, they are guaranteed to be in the same place.

Bell imagined that two observers, Alice and Bob, would share entangled pairs of photons and compare their measurements. When the two analyzers aren't aligned, the correlations between Alice's and Bob's measurements plummet. The remaining correlations can only be so strong if hidden variables determine the result of the measurement. They will be stronger. Experiments could prove the existence of hidden variables if they could observe correlations.

Clauser led a team that refined Bell's idea so that it could be applied to an experiment with calcium atoms. He and another colleague performed an experiment in 1972 in which they observed the extra-strong correlations predicted by quantum theory.

It's difficult to conduct such experiments as they need to rule out all influences that could allow the output of one analyzer to affect that of the other. Aspect and his team performed modified versions of the experiments in the 1980's. The loophole free experiment was performed in 2015.

If Clauser and Aspect used entanglement to prove that quantum mechanics is not as weird as they are made out to be, Zeilinger was the first to use it as a tool. In 1998, his team showed how it could take two pairs of entangled photons and swap theentanglement so that one photon from the first pair ends up entangled with one photon from the second. The exact quantum state of one photon to another could be instantly transferred using an ancillary entangled pair of photons.

The growth of quantum information science and quantum computing can be traced back to the work that was done. In the 1990s, Jian-Wei Pan was a graduate student at the University of Science and Technology of China. He says that people used to think that quantum information was fake. Information scientists didn't like it and basic researchers didn't like it It is one of the hottest areas in physics.

The prize underscores a prize that was never awarded. Pan says that John Bell should have been a winner of a prize. When he died, quantum information science hadn't yet come to light. The age of Bell's death was 62.