How Quantum Computers Work and What They Mean for our Computers
- Harshan Santhamoorthi
- Aug 12
- 3 min read
Check Glossary for terms you may not understand.
Many companies, including Microsoft, Google, and IBM, are producing quantum computers. But what even is a quantum computer? A quantum computer is a computer that
uses quantum mechanics to perform tasks. These tasks are not meant for normal computers. In an analogy by Cleo Abram, a video journalist known for her work in technology and science, she says computers are like cars and quantum computers are boats: neither one is better than the other. Each one just does a job the other doesn't do. But what makes a quantum computer do another job, because it's still a computer, right?
Well, our normal computers use a bit. A bit can represent two different possibilities: 0 or 1. Basically, it can represent one of those two values because it works on classical physics. Things must be zero or one, so it can only be one state at a time, meaning you're solving it
sequentially. So, when you are at a fork in the road, by yourself, one way is path 0, the other is path 1. You can't go both ways at once; you've got to try one before the other to know if that is the right or wrong. But what if we could just try both paths at once? That's what a quantum computer does, using a qubit, which can represent both 0 and 1 at the same time. Qubit uses the power called superposition, in which it can represent multiple possibilities at once. And now that it is in multiple states, we can use quantum parallelism to run all these possibilities. And then with all those possibilities, there will be right and wrong ones, so we use quantum interference to adjust our possibilities that are on a wavelength, so that the most likely answer will become the correct answer, and we will cancel out all the wrong answers by adjusting the wavelength for those possibilities so that they all cancel out. But to figure out the most likely possibility, we have to use a quantum oracle that flips the phase of the correct answer. And then when we use the quantum interference, the flipped phase wavelength will then rise, so it's the most likely. And then at the end, it checks with the Born rule, an important concept that allows you to predict the possibility of getting a certain result when measuring a quantum system. But now that we know how it works, why does a quantum computer not look like a normal computer?
Now this may look like a chandelier, but it's a quantum computer! All these tiny wires you see are cooling tubes, cooling the computer to -237.14°C. That big thing isn't the computer; instead, it's a little chip. Why so much for a little chip? Because for qubits to work, they need to be in a perfect state to work in. Things such as sound, which can cause mechanical vibration that can affect the qubit, as well as electromagnetic radiation can also cause unwanted disturbances to the qubits. Due to this, many people won't have to worry about getting one, because for day-to-day tasks, many people don't need to perform such impossible tasks. But companies such as Google, Microsoft, and
IBM are making them for other companies, such as their partners and collaborators, to buy for their use. Those companies use them in their research, in which it's not just for calculating; it can be used for finance, drug discovery, and cryptography. Michio Kaku, a theoretical physicist who was a New York Times best-selling author and is a professor at The City College of New York, says that it may be possible to find a theory that solves everything, from the creation of our universe all the way to the creation of life-even immortality-but because of how complex it is, we humans have not been able to solve that. That's where quantum computers come in. So, will you be a researcher one day, using a quantum computer to find a theory that solves everything?
Glossary:
Quantum Physics: The study of matter and energy at the most fundamental level.
Superposition: A qubit can be in both |0⟩ and |1⟩ at the same time, like a spinning coin before it lands.
Quantum Interference: Quantum waves can add up (boost answers) or cancel out (remove wrong ones), just like ripples in water.
Quantum Oracle: special gate that marks the correct answer by flipping its phase — without revealing it.
Quantum Parallelism: A quantum computer can process many inputs at once by using superposition.
Wavelength (Quantum Meaning): Not a real wave — but quantum states act like waves with peaks and valleys that can interfere.
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