Since the discovery of Quantum Mechanics, scientists have been looking forward to answer how subatomic particles work and cooperate. One of the biggest theory, if not the biggest of these cooperation-relation theory is Quantum Entanglement. In fact, this theory have been proved by Alain Aspect, John F. Clauser and Anton Zeilinger in 2022 and rewarded by 2022 Nobel Physics for experimentally showing the relation. Before getting into the details, we should start by having a quick understanding of necessary information.
What is Superposition?
We have to start by defining what superposition is to have good understanding of Entanglement concept. You might have heard the term Superposition defined by Erwin Schrödinger the famous Nobel Prize winner Physicist, with the analogy of “Cat in the box (aka Schrödinger’s cat)”. The concept is basically interpreted by if you haven’t measured something you can’t know if the event happened or not. If you want to learn deeply about it, you can find in our website soon.
Erwin Schrödinger
Source: lindahall.org
Schrödinger’s Cat
Source: wikipedia.org
Heisenberg’s Uncertainty Principle
Our other fundamental concept we will use in this topic is Heisenberg’s Uncertainty Principle. This principle tells that a quantum particle’s momentum and position cannot be measured at the same time. We will use this idea with other properties other than momentum and position too.
Werner Heisenberg
Source: physicsworld.com
Entanglement of Particles
Quantum Entanglement, tells us that specific particles such as electrons and photons can be correlated no matter how distant they are. This would be impossible according to classical physics because nothing can be faster than speed of light. That is why Einstein defined this relation as “Spooky action at a distance”. Quantum Entanglement shows us that this correlation of particles are contradictory. For example let’s take electron’s spin property. They have two possible spin. Spin+ or spin-. So if we measure one’s spin we automatically now the other one’s spin according to the theory.
The situation of oppositeness can also be interpreted different. It actually depends on how the experiment is designed. But the correlation is still there. According to Caltech Professor Thomas Vidick, the correlation can be without communication. In this scenario the theory of relativity won’t be affected or in other words speed of light won’t be taken into account. (1)
Visualization of Entanglement
Source: bigthink.com
Entanglement Simplistic Idea
Source: nancyannroth.com
The Experiment That Won Nobel Prize in 2022
As we stated at the very beginning, the entanglement has been proved by Alain Aspect, Anton Zeilinger,
John F. Clauser. The idea of this experiment goes all the way back to 60’s, to a CERN physicist John Stewart Bell. Bell proposed an inequality called “Bell’s inequality” and if this inequality was violated that meant that there were no hidden variable and quantum mechanics were true. This inequality and his thought experiment lead Alain Aspect and his colleagues to develop an experiment that would prove entanglement true. The experiment was basically sending two corelated photons emitted from calcium atom to two different polarizers and observe the behavior of these photons. With this experiment Aspect successfully violated Bell’s inequality and proved Einstein wrong.
Alain Aspect’s Entanglement Experiment
Source: wikipedia.org
Historical Overview
In 1932 three of successful classical physicists-Albert Einstein, Boris Podolsky, Nathan Rosen- published a paper interpreting Quantum Physics as true but not completed. EPR Paradox, which Einstein and colleagues published, was confronting the Copenhagen interpretation of Quantum Physics. He used term “spooky action at a distance” to define Entanglement. EPR paper caught attention among physicists which inspired Bohm’s interpretation and also Bohm’s inspired Bell’s inequality. (2)
Copenhagen Conference
Source: nbi.ku.edk
Authors of EPR
Source: entangledphysics.com
Future of Communication?
At the end, let’s come down to our Future quotation in the article. Since throughout the paper you might had an idea about using entanglement for communication and encryption. This is what researches trying to achieve in our modern communication era. Who knows, maybe one of you reading this would achieve.
Quantum Cryptography Image
Source: itsecuritydemand.com
References
- This reference is taken directly from scienceexchange.caltech.edu/topics/quantum-scienceexplained/entanglement the part “Relativity Remains Intact”. For further information you can check the paper from the link.
- This reference is taken from en.wikipedia.org/wiki/Quantum_entanglement#History. See more detailed information from the link.
Bibliography
- scienceexchange.caltech.edu/topics/quantum-science-explained/entanglement
- space.com/31933-quantum-entanglement-acBon-at-a-distance.html#
- physics.aps.org/arBcles/v8/123
- nobelprize.org/prizes/physics/2022/summary/
- arxiv.org/pdf/1306.3325#:~:
- youtu.be/9tSwddkLbZE?si=yKcIC_0cGxeP0cJi (This a Turkish video but it simply talks about Quantum Entanglement)
- erc.europa.eu/projects-staBsBcs/science-stories/how-entangle-two-electrons-and-do-it-again-and-again#:~:
- hquantumxc.com/blog/is-quantum-communicaBon-faster-than-the-speed-of-light/
- quora.com/Is-the-quantum-entanglement-effect-faster-than-the-speed-of-light#:~:
- en.wikipedia.org/wiki/Bell_test h”ps://en.wikipedia.org/wiki/Bell’s_theorem#:~:
- physicsworld.com/a/john-bell-profound-discovery-science/#:~:
- youtu.be/jSWfsESkyoo?si=uNhFAZ_T2EfdMOXz