Entanglement is one of the most important properties of quantum theory. In an entangled system, one particle determines the state of the other, regardless of how far apart the individual particles are.
The phenomenon is also known as ghostly action at a distance. Einstein did not want to believe in this effect, the experiments of the laureates made these states measurable and manipulable. The three physicists thus paved the way for the technical application of quantum theory. These are, for example, quantum computers and quantum communication.
Entanglement is perhaps the strangest phenomenon in quantum physics. Two entangled particles stay connected even if they are miles apart. When one changes status, the other also changes. Kind of like telepathy between photons.
The phenomenon was postulated by Albert Einstein along with Boris Podolsky and Nathan Rosen. The three themselves did not consider the phenomenon possible. They just wanted to show their colleague Nils Bohr how crazy quantum theory is. They were convinced that there must be hidden variables that could explain the relationship between the particles. However, representatives of quantum mechanics considered entanglement as a possible phenomenon.
To clarify who is right, Irish physicist John Steward Bell formulated a mathematical inequality in the 1960s that provided a criterion for deciding who was right: Einstein or the quantum theory he helped find.
John Clauser developed John Bell’s ideas into a practical experiment. His measurements supported the predictions of quantum theory. This proved that entanglement, or the “ghostly action at a distance” as Einstein ironically called it, could not be caused by hidden variables.
However, John Clauser’s experiment left out one aspect: the connected pairs could depend on a common source. Alain Aspect further modified and improved the experimental set-up so that the particle source could not influence the measurement results.
Anton Zeilinger eventually used the work of his colleagues to manipulate the states of entangled particles. His working group was the first to prove the phenomenon of quantum teleportation, which makes it possible to transfer the quantum state from one particle to another. In doing so, he created an approach to make quantum mechanics useful.
Anton Zeilinger demonstrated the first quantum cryptographically encrypted wire transfer in 2004. Just one of the many ways that quantum mechanics can be used. But it is not only the development of quantum computers that can process large amounts of data very quickly. Work is also underway on a bug-proof quantum internet.
It is not without reason that the European Commission has been supporting research into quantum technology with a billion euros since 2018 in a flagship project.
In an interview with Deutschlandfunk, Tomasso Calarco, co-founder of the flagship Quantum and professor at the Jülich Research Center, highlights the innovation potential that has emerged from the findings of the three laureates. Alain Aspect has himself set up a company that, in collaboration with the research center Jülich, should form the basic building blocks of a European infrastructure for quantum computing.
In contrast, before the three laureates’ experiments, work on the foundations of quantum technology was seen as “borderline philosophical,” says Tomasso Calarco.
Last year, three scientists shared the Nobel Prize in Physics: climate researchers Klaus Hasselmann and Syukuro Manabe were honored for their climate modeling and predictions of global warming. The third in the group, Giorgio Pairis, received the prize for his contribution to the understanding of complex systems.
Since its first award in 1901, the Nobel Prize in Physics has been awarded 115 times. Because several people are often awarded together, there are 214 prize winners and four prize winners.
The Nobel Prize in Chemistry will be awarded on Wednesday. The Literature Prize follows on Thursday, the Nobel Peace Prize on Friday and the Economics Award on Monday.
The founder of the renowned prize, Alfred Nobel, had made the non-profit nature of the research an important award criterion. Despite this fundamental humanitarian idea, the Nobel Prize is repeatedly criticized within science. This is because it is only awarded to individuals. But research is often teamwork. The attribution of individuals would foster a cult of personality and create false incentives.