In this blog post, we will take a closer look at why quantum computers, which operate based on the principles of quantum mechanics, are so much faster than conventional computers and explore their potential.
In February 2012, global IT giant IBM announced that it was close to developing a quantum computer and that commercialization was not far off, causing a huge stir. Research and development on quantum computers had been ongoing for some time. However, the fact that even a world-renowned company made such an announcement meant that quantum computers, which had been considered a “dream technology,” were becoming a 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 computers we use every day work. Conventional computers are based on the digital world, which represents two states: “1” and “0.” Semiconductors, the building blocks of the digital world, have continued to evolve, resulting in smaller and more powerful circuits in semiconductor chips. In other words, semiconductors are becoming highly integrated. With the steady advancement of semiconductors, the circuits in semiconductors will become smaller and smaller, eventually reaching the atomic and molecular level. However, in this microscopic world, quantum mechanical effects occur, where particles appear to have two states at once. In other words, in digital circuits that have entered the microscopic world, these quantum mechanical effects blur the boundary between “1” and “0.” This renders digital computers, which must operate with clear values, useless.
First, let’s take a closer look at the quantum mechanical effects that will lead to the replacement of current computers as semiconductor microtechnology advances. Quantum mechanical effects refer to the phenomenon in which a particle in the microscopic world can exist in two places at the same time. In other words, two states of a particle can coexist. Physicist Schrödinger’s cat thought experiment is a good example of this. A cat is placed in a box that is isolated from the outside world. An experimental device is set up inside the box that will kill the cat with a 50% probability using radiation. After a certain amount of time has passed, we do not know whether the cat is alive or dead, and can only predict its fate with a 50% probability. We can only know the cat’s condition when we open the box. In other words, until we observe it, the cat exists in a state of coexistence, or two states, as both “alive” and “dead.”
Quantum computers operate based on this principle of quantum mechanics. Quantum computers have introduced the term “qubit” as the basic unit of information processing, and a single qubit can exist in both a 1 and 0 state through quantum superposition. In other words, one qubit can express two states at the same time, and two qubits can express 2×2=4 states, while three qubits can express 2×2×2=8 states at the same time. Conventional computers can only express one state at a time. However, quantum computers, which can express multiple states simultaneously, enable tremendous speed improvements through revolutionary parallel processing, as well as the development of algorithms that cannot be implemented with conventional computers. In particular, quantum computers are expected to be useful for decryption. For example, if you want to enter a room with a 4-digit password, a conventional computer would try every possible combination from “0000” to “9999.” With a lot of luck, you might be able to enter the room before sunrise. However, a quantum computer would try all combinations from “0000” to “9999” at once, allowing you to enter the warm and cozy room immediately. In actual decryption, a task that takes 150 years with current computers can be completed in just four minutes with a quantum computer.
However, there are still obstacles that quantum computers must overcome. One of them is the “decoherence phenomenon,” which refers to the loss of quantum properties when quantum superposition is undone. This is equivalent to losing the characteristics of a quantum computer, and since decoherence is easily caused by minute vibrations and interference, it is a major issue in the development of quantum computers. In addition, technology must be developed to correct errors that occur when using quantum algorithms that can only be implemented by quantum computers. Quantum computers must not only be able to express multiple states simultaneously, but also be able to accurately select the state we need without error. Otherwise, it will be difficult to obtain the desired results, and quantum computers will be criticized for being “fast but inaccurate.” Other challenges include developing technology to maintain quantum superposition for extended periods of time and minimizing information loss during data transmission via quantum computers.
The introduction of quantum computers will bring about a radical change in the current computing paradigm. It will open up possibilities for solving problems that were previously impossible, and innovative developments are expected in various fields such as artificial intelligence, drug development, and financial modeling. For example, quantum computers can help develop new drugs by simulating extremely complex chemical reactions. This will enable tasks that would take hundreds of years with conventional computers to be completed in a short period of time.
In the past, Einstein rejected quantum mechanics, which relies on probability and chance, saying, “God does not play dice.” Unlike classical mechanics, which is based on the deterministic thinking of “either 1 or 0,” Einstein could not agree with quantum mechanics, which says that “it can be either 1 or 0.” However, current computers are reaching their limits and face 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 bring about the birth of “quantum computers.”
It will take a long time before quantum computers are commercialized for everyday use. However, the possibilities are endless, and research and development will continue. Even now, researchers around the world are working day and night to realize quantum computers. We look forward to the future that quantum computers will bring and will continue to monitor their development.
