Quantum Computing: How It Works

What is Quantum Computing? 

The advancement of technology and understanding of particle physics opens a new window of opportunities that presents itself in the form of quantum computing. You have probably noticed a rising trend of tech companies trying to build the first working quantum computer. However, what exactly is a quantum computer, and why is it so much better than the laptop you use for school? Quantum computing is an area of computer science that utilizes theories on the behavior of energy and matter at a very small scale (atomic and subatomic). The two main quantum theories that are important to know for now are superpositions and entanglement. Using the concepts of these two theories (and a few others), quantum computers can perform a myriad of functions that classical computers cannot. 

Feature 1 of Quantum computing: Superposition

Superposition is a phenomenon in which a particle can be in a combination of two states until a measurement is made. To understand superposition (and why it’s relevant), you must know how normal computing works. The smallest unit of information in classical computing is called a bit. A bit can store information as either a 0 or a 1. Quantum computing works in a similar way, instead with particles (ions, electrons, photons, etc) that represent a bit, otherwise known as a qubit. However, the difference between a qubit and a bit is that a qubit has the ability to be both 0 AND 1, while a bit can only be 0 OR 1. Imagine a qubit as a coin being flipped. When the coin is in the air, it is both heads and tails, not one or the other, but both at the same time. The qubit’s ability to be in a state of superposition allows it to store much, much more information than a bit, meaning as more qubits are used, the amount of information that can be stored increases exponentially which when compared to classical computers is a huge difference. 

Feature 2 of Quantum computing: Entanglement

Entanglement is a quantum effect where the state of two different qubits in a superposition directly affects each other when measured. When a qubit in superposition is measured, the state of superposition collapses so that the qubit is no longer in a state of 1 AND 0 but 1 OR 0 (whether the qubit collapses into a 1 state rather than a 0 state is probabilistic). If two qubits in superposition are entangled, when those qubits collapse into a 1 or 0, you only need to know the state of one qubit for the state of the second qubit to be immediately known. You can see this as two people (Alice and Bob) wearing hats. If you know that Alice wears a red hat when Bob wears a blue hat and Alice wears a blue hat when Bob wears a red hat, you know what color hat Alice is wearing even if you only see Bob that day. When particles are entangled, they can be seen as a single entity despite their distance. Entanglement is important in developing new technology because it significantly improves the speed in which quantum computers process information by its ability to transport information instantaneously. 

Types of Problems Quantum Computers Can Solve

Because of the massive computational power of a quantum computer (thanks to the theories of entanglement and superposition), quantum computers are able to solve complex problems that even a supercomputer is unable to solve. Quantum computers have the unique ability to solve problems with many many variables. Classical computers solve problems in a different way than we humans do. The way computers find solutions is by going through billions of operations per second and testing out every single possibility of a solution individually until the right answer appears. And this works a lot of the time until the number of possibilities of solutions becomes so great that even the best supercomputers are unable to solve it in a realistic amount of time. This is where quantum computers come in. Because quantum computers are able to store much more information and are faster, they are able to solve complex problems a lot faster. For example, finding the structure of proteins is a complex problem due to the numerous ways that amino acids can be connected and manners it can fold; however with quantum computing, finding the structure can be a lot faster which can revolutionize the medical field. 

Conclusion

In many ways, Quantum Computing is a groundbreaking field of science, redefining the boundaries of computational power. Taking advantage of our present understanding of matter and energy at atomic and subatomic levels, quantum technologies and concepts that were previously unimaginable have been now developed. However, these emerging technologies are still confronted by many difficult limitations – for instance, the environment. Due to the immense fragility of qubits, the presence of any external disturbances can alter the data considerably, leading to a loss of information. Consequently, many current quantum computers must be kept at temperatures nearing absolute zero (-273.15 C). Yet despite the challenges present, the potential of Quantum Computing is undeniable. Utilizing the theories of superpositions and entanglement, quantum computers may soon be able to take on a multitude of functions, ranging from Artificial Intelligence to Medicine. And wherever it is applied, fields and disciplines will experience immense breakthroughs, as humanity harnesses one of its most powerful tools yet.

Works cited:

Bowman, C. F. (2022). What is quantum computing? In How Things Work (pp. 215–234). Chapman and Hall/CRC.

Dargan, J. (2022, September 5). 81 quantum Computing Companies: The ultimate list for 2023. The Quantum Insider. https://thequantuminsider.com/2022/09/05/quantum-computing-companies-ultimate-list-for-2022/

Dilmegani, C. (2021, April 11). Quantum Entanglement: What is it & Why is it Important in 2023? AIMultiple. https://research.aimultiple.com/quantum-computing-entanglement/

Frankenfield, J. (2018, May 26). Quantum computing: Definition, how it’s used, and example. Investopedia. https://www.investopedia.com/terms/q/quantum-computing.asp

Vidick, T. (n.d.). What is entanglement and why is it important? Caltech Science Exchange. Retrieved January 3, 2023, from https://scienceexchange.caltech.edu/topics/quantum-science-explained/entanglement

Wilczek, F. (2016, April 28). Entanglement made simple. Quanta Magazine. https://www.quantamagazine.org/entanglement-made-simple-20160428/

You are being redirected. (n.d.). Analyticsinsight.net. Retrieved January 3, 2023, from https://www.analyticsinsight.net/top-10-unexpected-applications-of-quantum-computing-in-2023/