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Quantum computing explained with emojis

By in Features

Quantum computing positions itself to be a revolutionary way we process and use data with devastating implications for privacy and security. Being coated in unfamiliar lingo, quantum computing has slipped by as a seemingly fictional and far-fetched concept to the average person. Meanwhile, the race to build a fully-functioning quantum computer has picked up the pace significantly all over the world, especially among big players like Google and IBM. 

Quantum computing sounds terrifying — yes, most of us don’t even know how our normal, or “classical,” computers work. But rest assured, you don’t need to be an engineer or mathematician to understand it.

We are demystifying quantum computing with emojis. 

Quantum, or quantum mechanics, describes how the natural world works, much like Newton’s laws. The only difference is that quantum mechanics is so precise, it only matters in the microscopic world at the smallest scales while Newton’s laws only apply at macroscopic levels.

Computers process and store information in bits. You’ve probably heard of bytes (as in your 16-gigabyte smartphone, for example). Each byte contains 8 bits; the bit itself can only be one of two values — 0 or 1. For the purpose of explanation, we will present the bits with smiling and crying emojis, respectively. 

At the most simplified level, classical computation can be understood as performing logical checks — for example, “and” and “or” — on the bits. Here is a quick example with just two bits and two logic types:

In an actual computer, you will also get 0 or 1 output. The computer will translate the string of 0s and 1s to data that makes sense to you. For the sake of simplicity, our emoji computer will output the data directly. 

When we design our emoji computer, we don’t know which piece of information we want out of it. So we need to have at least four bits so that we can take all the possible paths to get to the result.

When we want to get an elephant, the computer can just take this path:

Everything is great, but each bit representing only one value is limiting. So here comes the qubit, or quantum bit, used in quantum computing. Qubits also store information, but each of them is both one and zero at the same time.

The special thing about qubit is when you measure it, it will take on one value — 0 or 1, but until then, it exists in a state of superposition between 0 and 1. Our emoji computer needs only two qubits to achieve the same number of possible outputs. 

The challenge for scientists and researchers everywhere is to reliably manipulate the qubits and keep them in the quantum state, where each qubit encodes two values, 0 and 1, simultaneously. Decoherence happens when the qubit is disturbed and caused to become a normal bit. 

To manipulate them, researchers rely on a process called quantum entanglement, where two qubits are so intrinsically tied together that when you measure one qubit, you can deduce the state of the other qubit as well no matter how far apart they are. 

Imagine the researchers entangle two qubits — let’s name them Bob and Bobby — to be always of opposite values. After entanglement, Bob is brought to North Pole and Bobby to the South Pole. If someone measures Bob in the North Pole, Bobby automatically takes on a value opposite to Bob, and vice versa. This process is so instantaneous and physically unusual that Albert Einstein famously dismissed it as “spooky action at a distance.”

That is the very basic, simplified version of quantum computing. If we scale this up, a classical computer needs 2n bits to have the same computational power as a quantum computer with n qubits where n represents a number. In fact, you only need about 70 qubits to store all the information available in all of the computers in the world right now, data centers included. 

Google recently announced they have achieved quantum supremacy — a milestone where quantum computers are proven to be superior to classical computers — with its 53-qubit Sycamore system. Their quantum computer system has performed an operation that would normally require classical computers 10,000 years in 100 seconds. 

IBM later responded by publishing a paper expressing doubts in Google’s claims. IBM’s estimates stake the computational operation performed by Sycamore as 2.5-day worth by classical computers. Still, quantum computing time of 100 seconds is impressive against 2.5 days. 

Regardless, we are now in what many call the second quantum revolution. Google predicts quantum computing technologies will expand at a “double exponential rate,” much faster than the progress in classical computing power. 

So what do we do with quantum computers? 

Quantum computers are especially good at factoring — or to jog your memory, finding all the prime numbers that multiply to a number. This matters because modern security and cryptography rely on the mathematical trap door: it is easy to multiply two prime numbers but difficult to factor the result. 

Your credit card information, for example, is protected by a large number that is a product of two randomly large prime numbers. Factoring this number takes classical computers 100,000 years on average, making it practically impossible to accomplish and ensuring your information is protected. 

This will change when quantum computers become reliable and big enough because it will only take them under eight hours to crack our today state-of-the-art security protocols. 

That said, this is not an immediate threat — back in May, IBM estimated that the commercialization of quantum computers takes three to five years. Even then, it’s unlikely that commercial quantum computers will be powerful enough to crack today’s security protocol. Along with quantum computers, researchers are also designing quantum security, making your information truly and fully secure. 

All worries aside, quantum computers hold the promise of revolution for every field out there. We can use its power to simulate quantum process in physics, chemistry and beyond. With our ability to understand atoms at the subatomic levels, we can design new medicines and better materials, thus exponentially improving our quality of life.

With their transformative potential, quantum technologies enjoy investments from governments and private sectors alike. Specifically, Canada aims to establish itself as the global leader in this emerging field, with over one billion being invested in quantum research and development over the last decade.

Most notably, Waterloo is supported by the federal and Ontario government to position itself as the world’s quantum valley. Claimed to be 15 years ahead of the quantum race, University of Waterloo’s Institute for Quantum Computing facilitates a cross-disciplinary and innovative research environment for more than 200 researchers, post-doctoral fellows and students.

Closer to home, the Centre for Quantum Topology and Its Applications, also known as quanTA, was established in the University of Saskatchewan in March with funding from Natural Sciences and Engineering Research Council of Canada and New Frontiers in Research Fund. With the expressed goal to bolster Western Canada as a competitive player in quantum science and technology, the centre focuses on the development of new quantum materials. 

Quantum computing is made increasingly accessible to researchers, developers, students and hobbyists alike via cloud-based systems. For example, IBM Q Experience provides access to up to 20-qubit processors and 32-qubit simulator. For those interested in getting started on quantum computing, IBM also provides excellent educational resources and tools. 

Humans tend to be scared of the unknown. Technology does not need to be inherently bad — it’s our use of it that gives it value. Quantum computing has a long way to go but it is set out to achieve remarkable things.

Minh Au/ Web Editor

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