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Quantum Computers: Surpassing the Limit

Nowadays, it is hard to imagine life without computers. It is not only desktops, but also laptops and smartphones that people use daily, that are high-performance computers. The same goes for government agencies and nations, too. Now, quantum computers have appeared and have begun to change the perceptions of what we thought were the limitations of computer abilities completely. Quantum computers are a future technology that is attracting attention all over the world. For example, the Massachusetts Institute of Technology’s (MIT) science magazine Technology Review in its April edition, selected the usage of quantum computers as the technology of 2018 that would make a profound change to peoples live. Following this revelation, the Sungkyun Times (SKT) now looks at what a quantum computer is and the principles underlying the technology. In addition, the SKT looks at the features and applicable fields of it and deals with developmental status and commercialization probabilities of quantum computing.

What Is a Quantum Computer?

Backgrounds of Its Appearance

A quantum computer is a computer which operates on the principles of quantum mechanics. It was first developed by the physicist Richard Feynman in 1982, in order to solve physics problems which were so complex that they were deemed unsolvable by any computer at that time. Quantum computers first appeared when the existing computers of the time reached their limitations. Computers have evolved along with the evolution of semiconductors. This is because semiconductors are used in the main parts of a computer, such as the CPU and the RAM. Since then, scientists have increased the ability of computers by increasing the number of components in semiconductors. They encountered another limitation, however, by just increasing the number of components. The space between the components narrowed as the number of them increased, resulting in a physical resistance phenomenon. That resistance disrupts the process of transferring information, so there was a limitation in improving computer performance. Although researchers have continuously tried to overcome this, they could not maintain the same speed of development as before. Furthermore, the data that people have to deal with is continuing to increase over the era of the Fourth Industrial Revolution. According to the Semiconductor Industry Association (SIA), by the 2040s, it is predicted that people will not be able to deal with the large amounts of data with the current speed of computer development and this will result in huge amounts of consumption. Therefore, the need to develop a new kind of computer became more important, and thus the quantum computer was developed.

Principles of Quantum Computers

Whereas existing computers are based on classical mechanics, quantum computers are based on quantum mechanics. A “quantum” is the smallest unit of all physical entities involved in interaction, and quantum mechanics is the theory that explains how they apply. In the world of quantum mechanics, there are unique phenomena that cannot be observed in reality, and the quantum computer applies two phenomena among those. The first one is quantum superposition. In the microscopic world, where quantum mechanics is dominant, it is possible to exist and not exist at the same time. Schrödinger’s cat is a typical example that explains this phenomenon. Assume that a cat is in a sealed box, and there is a 50% probability that poison gas will spread inside the box after five minutes. In classical mechanics, a cat will live or die, only one state among the two will be correct. In quantum mechanics, on the other hand, the life and death of the cat coexists until someone looks inside the box. The second principle is quantum entanglement. It literally means that two or more quantum states are closely bound together. In the entangled state, quanta influence each other at a speed 10,000 times faster than light. In other words, two quanta move as though they are one.

Quantum Entanglement/ heybd.tistory.com

Features of Quantum Computers

Bit of Computer and Qubit of Quantum Computer/ steemit.com

Due to the principles beneath quantum computers, they have unique features. Whereas exist ing computers use a unit of “bit” to store and process information, a quantum computer uses a new unit, a “qubit”. Using a bit, the existing computer answers all questions using only 0 and 1 and expresses only one state at a time. Even if multiple bits are combined, only one state can be expressed at any one time. Through quantum superposition, however, a qubit can express 0 and 1 at the same time. Also, by quantum entanglement, the qubits interact immediately with each other as if they are one. Thanks to these principles, it is possible to represent many states at once and process large amounts of information in a short period of time. For example, suppose there are 10 bits and 10 qubits each. That would mean that a total of 210, 1,024 numbers can be presented with 10 bits. Existing computers can process only one input at a time, so they need do the same process 1,024 times. A quantum computer, however, can process those 1,024 inputs at once by overlapping them. That is, with 10 qubits, the calculation speed is 1,024 times faster, and the speed becomes even faster as the number of qubits increases. Quantum computers with 50 qubits can achieve a faster processing speed quicker than any other supercomputer. For instance, the quantum computer “D-WAVE 2X” developed in 2015, operates at 100 million times faster than a supercomputer. The Nobel Prize-winning physicist Serge Haroche said, “Human beings can quickly achieve the technology developments needed for an aging society through quantum computers, such as the development of new drugs or artificial organ research that processes hundreds of thousands of chemicals.”, optimizing the prospects of quantum computers.

Process of Quantum Computer/ heybd.tistory.com

Availability of Quantum Computers and Development Status

Fields of Application

Quantum computers are optimized to handle complex data, making themselves effective in solving geometrical problems. A geometrical problem is a problem where the size increases sharply as the number of variables or factors related to the problem increases. For instance, suppose a person is going to tour 50 different areas and is considering creating the most efficient route. There would be hundreds to thousands of factors to think about such as the purpose of the tour, the nature of the path, and the presence of obstacles. Since it has more than 1,000 trillion possibilities, it has been difficult to calculate those using existing computers, but a quantum computer can do the job, instead. A typical field of exponential problems is in drug development. When developing a new drug, even when analyzing only one protein, researchers need to calculate the interactions of all atoms and electrons one by one. In this process, using a quantum computer can dramatically shorten the time it takes to develop a new drug. For example, DNA-SEQ, a company developing cancer therapy, introduced quantum computers during the simulation process of drug development. As a result, it was able to reduce the number of patients needed for clinical trials and development costs. Quantum computers can be used in the transportation field, as well. Volkswagen, for example, introduced a quantum computer to optimize the traffic flow of 10,000 cars in Beijing, China last year.

Development Status

It is expected that there will be a huge market within the quantum computer sector in the near future. Park Young-soo, senior researcher at the Electronics and Telecommunications Research Institute (ETRI), expected that the size of the quantum computer market will reach $23.6 billion by 2025. In preparation for this increase, countries are focusing their efforts into quantum computer research. The United States (US) has already secured the technology and is working to apply it to various industries. For instance, physicist John Martinis in cooperation with Google, wrote “AI speed improvement through quantum computers” with added support from the government. China launched the world’s first quantum telecommunication satellite “Mukza” in June and succeeded in using quantum computers at a distance of 7600 km. In addition, China plans on completing the world’s largest quantum research center, investing \13 trillion by 2020. Compared to these countries, however, Korea does not have much national support. According to the ETRI survey, there is a technological gap of about eight years between Korea and other developed countries like the US. Currently, the Ministry of Science and Information & Communication Technology (ICT), and several university professors have joined for a project worth \300 billion, and the project is under feasibility evaluation now. If the project is adopted, participants will work together to create a quantum computer over eight years and develop related technologies as well.

D-Wave 2X/ skyilcts.tistory.com

Can Quantum Computers Be Commercialized?

Quantum computers are just starting to be commercialized, and the price of one computer is about \10 billion. Therefore, only large corporations with sufficient money are using quantum computers now. In December 2017, Samsung and J.P Morgan Chase & Co introduced the “Q-system”, a 20-qubit quantum computer commercialized by the computer company International Business Machines Corporation (IBM). It is, however, still a time-consuming situation to put a quantum computer into practical use in everyday life. For that, there are some obstacles to overcome.

Technical Improvements

First of all, there is a need for a technology that can efficiently maintain the qubit. It is difficult to maintain a qubit for a long time using current technologies. Therefore, only a very limited level of ability can be achieved now. In order to keep the qubit as long as possible, it is necessary to create an extremely low temperature and a vacuum sealed state.

Quantum Telecommuncation Satellite “Mukza”/ hani.co.kr

In addition, there is a need for the facilities to locate the qubit to block it from being affected by the external environment. A lot of money is spent to create those environments, so it is necessary to reduce costs by developing efficient and economical technology. Software issues should also be resolved. Quantum mechanics, the basis of a quantum computer, basically expresses the motion of a quantum using probability. Unlike the real world, this probability can be negative, or even complex. Since the probability of negative and complex numbers cannot be used, it causes decreases in accuracy, and even errors occur. In order to minimize those errors, it is necessary to improve algorithms in software. At a conference in the US, Microsoft introduced a new programming language designed for quantum computing. Experts hope that an effective algorithm can be created using the new programming language.

Conflict with Existing Encryption Technology

As more and more quantum computers are introduced, the digital cryptography system, which is now widely used in many important fields, needs to be fundamentally changed. Current cryptographic techniques require decimal decomposition when decrypting. Because of the difficulty of calculation, it has been safe from decryption so far even with a supercomputer. However, quantum computers can penetrate the security within only a few months through their improved computational speed. If exploited, they can be used as unbreakable hacking weapons. If a country such as North Korea penetrates the Korean encryption system using a quantum computer, that society would be paralyzed. In the case of Bitcoin, the user proceeds with a transaction by creating two numbers, a private key and a public key. In order to pass through the security, people must find the private key through the public key. This is very difficult for conventional computers, but the quantum computers can do it very easily. Against quantum computers, as a result, technicians have created a “byte ball” to maintain the existence o f c r y p t o c u r rency. As such, other fields need to devise a new cryptosystem that can be safe from a quantum computer being used for hacking purposes.

Quantum computers are actualizing what people could have only imagined. Someday, they will change human life completely. The SKT hopes that Kingos recognize the potential of quantum computers, but also pay attention to their potential issues.

안광제  rhkdwp8066@skku.edu

<저작권자 © THE SUNGKYUN TIMES, 무단 전재 및 재배포 금지>

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