How do quantum computers change the existing computing paradigm and how will they shape our future?

Unlike traditional digital computers, quantum computers utilize the principles of quantum mechanics to maximize parallel processing power. This enables revolutionary advances in various fields such as cryptography, artificial intelligence, and drug development, and the commercialization of quantum computers is expected to revolutionize human society.

 

In February 2012, IBM, a global IT company, announced that it was close to developing a quantum computer and that commercialization was not far away. Research and development of quantum computers had been going on for some time. However, the fact that a major global company announced this news means that quantum computers, which were once considered a ‘dream technology’, are approaching reality. Let’s take a closer look at what quantum computers are and how amazing they are.
To understand quantum computers, we first need to understand how the classical computers we use every day work. Classical computers are based on the digital world of “1s” and “0s,” representing either/or states. Semiconductors, the materials that make up the digital world, have been continuously improving, allowing for smaller and more powerful circuits on a semiconductor chip, which means that semiconductors are becoming highly integrated. As semiconductors continue to improve, the circuits on them get smaller and smaller, until one day they reach the atomic and molecular levels. However, in this microscopic world, quantum effects, the phenomenon where particles can take on two appearances at once, are present, and in digital circuits, the boundaries between “1” and “0” are blurred due to these quantum effects. This makes digital computers, which are supposed to work with unambiguous values, useless.
First, let’s take a closer look at the “quantum effect” that will lead to the “firing” of current computers as the microtechnology of semiconductors improves. The quantum effect refers to the phenomenon that a particle can be in two places at the same time in the microscopic world, meaning that two states of a particle can coexist. Physicist Schrödinger’s cat thought experiment is a good example to understand this. A cat is placed inside a box that is isolated from the outside world. Inside is an experimental device that uses radioactivity to kill the cat with a 50% chance of dying. We don’t know whether the cat is dead or alive at the end of a certain amount of time, only that there is a 50% chance that the cat is alive. We only know the state of the cat when we open the box, i.e., until we make an observation, there are two states coexisting, one that is ‘alive’ and one that is ‘dead’.
Quantum computers work based on these principles of quantum mechanics. Quantum computers introduce the term “qubit” as the basic unit of information processing, and a qubit contains the states of 1 and 0 coexisting through quantum superposition, meaning that one qubit can represent two states simultaneously, two qubits can represent 2×2=4 states, and three qubits can represent 2×2×2=8 states. Traditional computers can only represent one state at a time. However, quantum computers can represent multiple states simultaneously, which allows for dramatic parallelism, resulting in tremendous speedups and the development of algorithms that are impossible to implement on conventional computers. In particular, quantum computers are likely to be useful in cryptography. For example, if you want to get into a room with a four-digit password, a classical computer would have to try every possible number starting from ‘0000’ and ending with ‘9999’ and, if you’re very lucky, you’ll be in the room before the sun comes up, but a quantum computer could try ‘0000’ to ‘9999’ all at once and be in the warm, cozy room in no time. In fact, it would take a quantum computer just four minutes to crack a code that would take a current computer 150 years to crack.
However, there are still mountains to climb for quantum computers. One of them is decoherence, which is when a quantum superposition unravels and ceases to act as a quantum. This is a major problem in the development of quantum computers because they are susceptible to even the slightest vibration or interference. In addition, techniques must be developed to correct errors that occur when using quantum algorithms that only quantum computers can implement. Quantum computers must not only represent multiple states simultaneously, but also be able to accurately select the state we need from among them without error. Otherwise, we won’t get the results we want, and quantum computers will be labeled as “so fast and so much work, but it’s all crap. Other challenges include developing technologies to ensure that the quantum superposition state can be maintained for a sustained period of time, and minimizing information loss when transmitting data through quantum computers.
The introduction of quantum computers will radically change the current computing paradigm. It will open up the possibility of solving problems that were previously impossible, and revolutionary advances are expected in fields as diverse as artificial intelligence, drug discovery, and financial modeling. For example, quantum computers could help develop new drugs by simulating highly complex chemical reactions. This could be done in a fraction of the time it would take a classical computer, which could take hundreds of years.
In the past, Einstein dismissed quantum mechanics, which relies on probability and chance, by saying that God doesn’t play dice. Einstein disagreed with quantum mechanics, which is based on the deterministic idea of “1 or 0!” as opposed to classical mechanics, which is based on the idea of “it could be 1 or 0”. However, current computers are facing the limits of their development and have various unsolvable problems. To overcome this situation and bring about revolutionary changes in information technology and human society, God has already started playing dice to create a quantum computer.
It will still be a long time before quantum computers are commercialized in real life. But the possibilities are endless, and research and development will continue for years to come. Even now, researchers around the world are working day and night to make quantum computers a reality. We can’t wait to see what the future holds for quantum computers, and we’ll have to wait and see how they develop.