The three scientists who won the Nobel Prize in Physics - French scientist Alan Aspe , American scientist John Crowze, and Austrian Scientist Anton Salinger . They demonstrated the potential of particles in an entangled state through groundbreaking experiments. The development of experimental tools by these three winners also laid the foundation for a new era of quantum technology.
Alan Aspe (left), John Crowze (center), Anton Salinger (right). Image source: Nobel Prize official website
Do you understand "entanglement"?
In the so-called "entangled pair", what happens to one particle will determine what happens to another particle (no matter how far apart). what does that mean?
entanglement diagram.
The basis of quantum mechanics is not just a theoretical or philosophical question. It is closely related to quantum computers, improved measurements, quantum networks and quantum encrypted communications that are being intensively developed around the world and are constructed by using the special properties of a single particle system.
and above all need to rely on how quantum mechanics allows two or more particles to exist in a shared state, even if they are separated by thousands of mountains and rivers, they can maintain this state.
This is called entanglement.
It has been one of the most debated elements in quantum mechanics since the theory was proposed.
Two pairs of entangled particles are emitted from different sources. One of the particles in each pair of particles gathers together in a special way. Then the other two particles (1 and 4 in the figure) are also entangled. In this way, two particles that have never been in contact can be entangled together.
Albert Einstein said this was "ghostly action beyond distance", while Elwin Schrödinger said this was the most important feature of quantum mechanics.
This year’s winners explored these entangled quantum states. Their experiments cleared the obstacles for new technologies based on quantum information and laid the foundation for the ongoing quantum technology revolution.
Continuously resolves the vulnerability
A long-standing question is whether the correlation is because the particles in the entangled pair contain hidden variables. In the 1960s, John Stewart Bell proposed the mathematical inequality named after him. This means that if there are hidden variables, the correlation between a large number of measurements will never exceed a certain value. However, quantum mechanics predicts that some type of experiment will violate bell inequality , resulting in stronger correlations than other methods.
Entangled pairs of quantum mechanics can be compared with machines that throw opposite color balls in the opposite direction. When Bob caught a ball and saw it was black, he immediately knew Alice had grabbed a white one. In the theory of using hidden variables, the ball always contains hidden information about what color to display. However, quantum mechanics says that the balls are gray until someone looks at them, one randomly turns white and the other turns black. The Bell inequality relationship shows that there are experiments that can distinguish these cases. Such experiments prove that the description of quantum mechanics is correct.
John Crowze developed Bell's idea and measured it through a practical experiment, which supported quantum mechanics by clearly violating Bell's inequality. This means that quantum mechanics cannot be replaced by the theory that uses hidden variables.
John Crowze research diagram.
After John Crowze's experiment, some vulnerabilities still exist.Alan Aspe developed a new setup and used it in a way that would make up for important vulnerabilities. He is able to switch measurement settings after the entangled pair leaves its source, so the existing settings will not affect the results when they are emitted.
Alan Aspe research diagram.
Using improved tools and a series of long-term experiments, Anton Salinger's team used entangled quantum state to prove a phenomenon called quantum teleportation, which can move quantum states from one particle to another at a distance.
Anton Salinger research diagram.
" entangled state " is moving from theory to technology
quantum mechanics has begun to be applied and has produced a broad research field, including quantum computer , quantum networks and more secure quantum encrypted communication.
From a practical perspective, quantum entanglement represents actually a huge resource. Scientists’ dissatisfaction with quantum entanglement loopholes stems from the lack of application ranges at each stage.
Anders Ilbeck, chairman of the Nobel Committee on Physics, concluded: "It is becoming increasingly clear that a new type of quantum technology is emerging. We can see that the work of winners in entangled states is very important, even beyond the basic questions about quantum mechanics explanation."
Source: Science and Technology Daily
