(Sebastian Sousa, St. Patrick’s School of Santo Domingo, Dominican Republic)
Introduction
Have you ever experienced an eerie coincidence? Thinking of someone just as they call or mirroring their actions at the same time by accident? While this sort of simultaneity may seem like just a strange coincidence, in the quantum world it isn’t. Particles experience an actual, measurable connection, no matter the distance (see Figure 1). This phenomenon is called quantum entanglement, and it is what drives scientists crazy. This discovery has challenged the understanding of causality that we hold in physics and overall reality, and it could reshape the way we explore the universe. There is a famous quote by the one and only Albert Einstein that called quantum entanglement “spooky action at a distance.” That is because this physical phenomenon defied his discovery of light speed as the ultimate limit of the universe, and he had no reasonable way to explain it. This discovery has fascinated me since I learned about it because it broke all philosophical concepts of physics and reality.
Fig. 1 In the quantum phenomenon known as entanglement, the properties of two particles are intertwined even if they are separated by great distances from each other. (Credits: Natasha Hanacek, National Institute of Standards and Technology [NIST])
Background
To start explaining quantum entanglement, we must first understand what entanglement even is. If we take 2 coins and hold them each in a different hand, they’re not entangled. This is because if we flip each coin, it will have a 50% chance of landing on heads or tails, and it will remain true no matter if you look at the other coin or if you do not. If we entangle these coins, then when one coin comes up heads, the other one will instantly come up tails. How can that even happen? Well, you can entangle particles by holding them so close together that their quantum state and their destiny are then shared. It does not mean that they are close together physically, but that their quantum state is now close to each other. This means that if you were to take 2 quantum entangled particles and assign them each to 2 rockets and send those rockets opposite each other at light speed as far as you could, those 2 particles would still be linked. If one of those particles behaves a certain way, the other will respond to it instantly. No matter how long it takes for light to reach the other rocket , the particles will react faster.
This immediate action at a distance went against everything Einstein had relied upon when formulating his theory of special relativity. In fact, such simultaneity between widely separated events defied the basic principles of relativity, where the constancy of the speed of light in any reference frame forms the basis of all subsequent phenomena. According to Einstein, there is no possible way to gain information about something if the light carrying that information has not yet reached you. So how is this able to happen? It is because their destiny is shared. Recently, scientists have figured out how it worked, and oddly enough, it was a groundbreaking discovery. They figured if they could somehow entangle particles and send them far from one another, it could basically allow for instantaneous communication between people who in the future will be great distances apart. This was an amazing feat of science, and people thought they were ascending to a new level of technology.
However, this predicted capability is partly wrong. They did manage to create quantum entangled particles, but they couldn’t use them for instantaneous communication. See, the method itself would be easy. Take a group of quantum entangled particles and separate them; have 2 observers at each end make the observations to then decode the signal to the agreed-upon encoding, right? No. The problem falls apart when you try to decode it. To do this, you’ll need to observe it, and just observing or measuring a particle will change its quantum state. This is the sole issue with quantum states. When you observe them, they’ll break their bonds since their states will be altered. Before being observed, these particles will remain in a random state of superposition. A superposition state is when the particle does not have a set state until it is observed, or measured, at which point the superposition collapses into a single state.
Possible Applications
So, now that we know what quantum entanglement is and some reasons as to why people think it is not an effective means for instantaneous communication, let’s talk about what it can do. Experiments with particle accelerators and aboard satellites have shown that photons and other fundamental particles can be entangled and so have confirmed the potential for significantly higher-speed and more secure communications (see Figure 2).
Fig. 2 An experiment in 2017 used the Micius satellite to successfully link communications between two stations in China via quantum channels involving entangled photons. (Credit: Micius Team)
The famous Microsoft chip that literally created a new state of matter (Majorana) uses quantum mechanics involving qubits to solve highly complex problems in chemistry, material science, and space science. One of the reasons this quantum computer is an astonishing feat is because it will revolutionize robotic and manned exploration of space. The exploration of distant planets and stars is known to need the most complex calculations to succeed. These calculations are usually done by a computer, but external interferences such as noise, temperature fluctuations, and even nearby phone or device signals can cause mistakes. Space scientists say even the slightest miscalculations can easily cost the lives of people, not to mention the expenses. Majorana’s particles, however, are uniquely identical to their antiparticles, thus enabling a fascinating multiplicity of quantum states that are resistant to external disturbance. This means that the particle is not in one state and place at one time, so it’s insanely harder for an interference to happen.
Additionally, data can be stored way better, and space simulations can run faster. Since the bits of data are entangled as qubits, they can both represent 0 and 1 at the same time, allowing for more complex calculations. See, normal computers must go through the process of checking every single outcome, and this process is normally very slow. Entangled qubits (quantum bits) give you a superposition where it shows all possible outcomes as data and the most probable one to happen. Once the most likely result emerges, then the quantum bit is measured. As said before, once measured, the superposition of possible states will collapse, and the qubit will no longer be in that superposition state.
Microsoft’s Majorana chip has the potential for realizing this type of achievement. Chetan Nayak, the former General Manager of Quantum Hardware at Microsoft, has stated the following: “Our roadmap now leads systematically toward scalable QEC (Quantum Error Correction). The next steps will involve a 4×2 tetron array. We will first use a two-qubit subset to demonstrate entanglement and measurement-based braiding transformations. Using the entire eight-qubit array, we will then implement quantum error detection on two logical qubits.” To put it simply, he aims to create an 8-qubit structure that can successfully correct its own errors based on the response from the 4 pairs of entangled qubits.
Conclusions
To sum up this whole essay, quantum physics and especially quantum entanglement comprise one of the greatest mysteries of science, reality, and even philosophy. Proposed uses, like instantaneous communication, remain impractical. Meanwhile, the true power of quantum entanglement lies in its ability to drive breakthroughs in fields like encryption and space exploration. It can also help in studying particles and their destiny, and can even be used to create space simulations and other calculations at much greater speeds. “Nature is pleased with simplicity,” as Sir Isaac Newton once said, and quantum entanglement beautifully embodies this quote. The simplicity of nature will always whisper to us the answers to the cosmos, leaving us to listen, learn, and create.
Sebastian Sousa wrote this essay as an 11th grade student at St. Patrick’s School of Santo Domingo in Santo Domingo, the capital city of the Dominican Republic. He credits his teacher, Marleshka Maradei, as his reference.
Bibliography
Bolgar, Catherine. “Microsoft’s Majorana 1 Chip Carves New Path for Quantum Computing.” Source, 19 Feb. 2025, news.microsoft.com/source/features/innovation/microsofts-majorana-1-chip-carves-new-path-for-quantum-computing.
Mack, Katie. “Quantum 101 – Quantum Science Explained” | Perimeter Institute. perimeterinstitute.ca/outreach/general-public/quantum-101.
Nalick, Jon. “Untangling Quantum Entanglement — Caltech Magazine.” Caltech Magazine, 11 Oct. 2019, magazine.caltech.edu/post/untangling-entanglement.
Nayak, Chetan. “Microsoft Unveils Majorana 1, the World’s First Quantum Processor Powered by Topological Qubits.” Microsoft Azure Quantum Blog, 19 Feb. 2025, azure.microsoft.com/en-us/blog/quantum/2025/02/19/microsoft-unveils-majorana-1-the-worlds-first-quantum-processor-powered-by-topological-qubits/?
Sen, Aditi. “Quantum Entanglement and Its Applications.” Current Science, vol. 112, no. 7, 2017, pp. 1361–68. JSTOR, www.jstor.org/stable/24912680.
Siegel, Ethan. “No, We Still Can’t Use Quantum Entanglement to Communicate Faster Than Light.” Forbes, 2 Jan. 2020, www.forbes.com/sites/startswithabang/2020/01/02/no-we-still-cant-use-quantum-entanglement-to-communicate-faster-than-light.
Vimal, Vimalesh Kumar, and Jorge Cayao. “Entanglement Measures of Majorana Bound States.” Physical Review. B./Physical Review. B, vol. 110, no. 22, Dec. 2024, https://doi.org/10.1103/physrevb.110.224510.