Quantum Computing in ELI5 terms
Explain like I’m 5 years old: qubit, quantum computing, quantum algorithms, quantum supremacy, post-quantum cryptography, quantum-safe security
What is a quantum computer?
You may have heard the term Quantum Computing (QC) quite a lot in recent months, as it’s becoming in fact the media buzz surrounding AI technologies. QC emerges as potential game-changer, especially in context of cryptography and digital security. With ability to solve complex problems much faster than classical computers, QC holds the challenge of breaking current encryption methods, leading us into new era of cybersecurity concerns.
So what does it mean a quantum computer? What is a qubit, superposition, entanglement and other fancy quantum stuff? In this article I’ll try to explain these basic QC terms, following the ELI5 (Explain Like I’m 5 years old) method. Although my daughter is about that age, she is not much into computers (“boring”), especially quantum ones, so I have not managed to verify this and get her approval for publication. I’m working on this :)
In the meantime...
Quantum Computers
Imagine you have a magic coin for playing a guessing game. Normally, when you flip a regular coin, it can either be heads (like the top of your head) or tails (like a little tail). But this magic coin is super special because it can be heads, tails, or both at the same time when it's spinning in the air!
In a computer like the one you use to play games or watch cartoons, it uses normal coins that are either heads (0/false) or tails (1/true) to make decisions. But a quantum computer uses these magic spinning coins, which we call qubits. Because these qubits can be heads, tails, or both, they can do much more powerful and interesting things than regular computers can. It's like having a superpower to solve puzzles and problems really fast!
Just remember, while our magic coin is super cool, it's also very delicate. It needs to be kept in a very special place (a magic castle) so it doesn't stop spinning until we're ready to see if it's heads, tails, or both. That's why scientists are working hard to make quantum computers better every day, using these amazing magic coins!
Qubit
A qubit is like your magic coin. In regular computers, you have bits that are like regular coins, they can be only heads or tails. But qubits, like your magic coins, can be heads, tails, or both when they’re spinning. This makes them MUCH MORE powerful for doing computer stuff.
Superposition
Think of it like your magic coin spinning in the air. While it's spinning, it's not just heads or tails, it's both at the same time! This is like a superpower for the coin, letting it do many things at once. Imagine wearing two different Halloween costumes at once, for example you could be a princess and a unicorn at the same time! Wouldn’t it be awesome?
Entanglement
Imagine you have two magic coins that are linked together by a magical force. Whatever you do to one coin, the other one feels it too, even if they are far away from each other. It's like they have a secret way of talking to each other! Exciting, isn’t it?
Measurement
This is like catching the spinning coin in your hand and seeing if it's heads or tails. Before you catch it, it's spinning and can be both. But once you catch it, it has to decide to be either heads or tails. This is when the magic coin's superpowers are revealed.
Noise
Noise in quantum computing is like if someone is shaking the table while you're trying to balance your spinning coin. It makes it harder for the coin to keep spinning properly. In quantum computers, noise can mess up the magic coins (qubits), so scientists work really hard to keep things very quiet and stable for them.
Quantum Algorithm
Think of this like a special set of instructions or a recipe for your magic coins. It tells them exactly how to spin, flip, and interact with each other to help solve really tricky puzzles.
Quantum State
This is a fancy way of talking about what your magic coin is doing. Is it spinning? Is it heads or tails? All the different ways the coin can be are its quantum states.
Quantum Supremacy
Imagine you have a super fast race cars (quantum computers) and lots of regular cars (classical computers). Now, there’s a really big and complicated maze that all these cars have to solve. The regular cars can go through the maze, but it takes them a very long time because the maze is super tricky. But the super fast race cars, because they’re so special and fast, can zip through the maze and solve it super quickly, much faster than any of the regular cars can.
This is like a magic trick that only the race cars can do because of their special powers. When the race cars show they can solve this maze faster than all the regular cars, they’re proving they are the best at this type of maze. It’s when the quantum computer (the race car) shows it can do a specific job faster or better than any regular computer can.
Quantum-Safe Security
Imagine your friend has a box of treasure, and they have a magic shield around it so no one can take the treasure away. Now, some people are making a super strong magnet (like a quantum computer) that can go through the shield and take the treasure!
Quantum-safe security is like making a new kind of shield around the treasure box. This shield is so strong and clever that even the super-duper strong magnet can’t get through it. It means making sure the treasure is safe, even from the most powerful magnets out there. So, with quantum-safe security, everyone’s treasure can stay safe and sound, no matter what!
Post-Quantum Cryptography
Now imagine you have a secret clubhouse with a super special lock that only you and your friends know how to open. Right now, the lock works great because no one else can figure it out. But you’ve heard that someone is building a magic key (this is like a quantum computer) that can open any lock in the world, no matter how special it is.
Post-quantum cryptography is like making a new kind of lock for your clubhouse. This new lock is so special that even the magic key can’t open it. It’s like creating a puzzle that’s so tricky, not even the smartest magic key can solve it. So, even when someone gets the magic key, your clubhouse secrets are still safe. That’s what scientists are working on: making sure our secret clubhouses stay safe, even from magic keys!
Want to learn more?
Alright, I hope I could translate this quantum gibberish into something more approachable. However, the quantum computing is based on principles of quantum physics, don’t get used to ELI5 explanation for everything related to this emerging technology.
In follow-up articles I will try to explore some of the practical use cases of quantum computing and development of quantum algorithms, as well as accessing the simulators and real quantum hardware (QPU) with cloud services like IBM Quantum Platform, Amazon Brackets, Azure Quantum, and many others.
As the quantum technology is currently still evolving, there are a lot of advancements happening literally on daily basis, so I think it’s about time to dive deeper into quantum computing to understand the technology better. If you want to follow up on the topic and soak in some quantum knowledge, here are few of the resources I found particularly useful.
Quantum computing concepts:
IBM Quantum Learning
https://learning.quantum.ibm.com/Black Opal
https://black.q-ctrl.com/
Quantum algorithms development:
IBM Quantum Documentation
https://docs.quantum.ibm.com/Penny Lane
https://pennylane.ai/qml/
Cheers,
Qubit Ninja