History and Challenge for Quantum Computing

- Overview

In 1981, at Argonne National Laboratory, a man named Paul Benioff exploited Max Planck's idea that energy exists in a single unit, and matter exists in a single unit, thus giving rise to quantum computing. Concept has been theorized. Since that year, with new technological advances in quantum theory, the idea of making quantum computers for everyday use has become more concrete. 

- A Brief History of the Future

In 1936, Alan Turing proposed the Turing Machine, which became the basic reference point for computing and computer theory. Around the same time, Konrad Zuse invented the Z1 computer, considered the first electromagnetic binary computer. What happened next is history, in our world today, computers are everywhere. 

The main catalyst behind this transition is the discovery of silicon and its use in producing high-quality transistors. This happened over a period of 100 years, from Michael Faraday's first recording of the semiconductor effect in 1833, to Morristanenbaum, who made the first silicon transistor at AT&T Bell Labs in 1954, to the first integrated circuit in 1960. 

We are about to embark on a similar journey in our quest to build the next generation of computers. In the early 1980s, Richard Feynman, Paul Benioff, and Yuri Manin laid the foundations for an entirely new paradigm of quantum computing, which they believed had the potential to solve problems that "classical computing" couldn't. Thus, quantum computing came into being. Quantum computing can change the world. It could transform medicine, crack encryption and revolutionize communications and artificial intelligence. 

Quantum physics, which emerged in the early 20th century, is so powerful yet so different from anything previously known that even its inventors struggled to understand it in detail. Similar to the trajectory that non-quantum communications took over 100 years from discovery to large-scale use, quantum computers are now maturing rapidly. Today, many players are fighting a battle over who can build the first powerful quantum computer.

- Why Do We Need Quantum Computing?

Quantum computers, sometimes called probabilistic or nondeterministic computers, are considered the most important computing technology of this century. It is a computing marvel that harnesses the natural world to produce machines with powerful processing potential. Our world and reality itself is quantum. Real-world quantum systems cannot be modeled on classical computers. 

Today's digital technologies are basically arithmetic devices that perform mathematical operations. We benefit greatly from computing in all its forms. Computers are very important in our life. Hardware and software are what keep each object functioning properly. However, they have some limitations, which is why we need quantum computers. 

Although the name sounds complicated, it is not difficult to define. It is a machine that uses the properties of quantum physics to store data and perform computations. They perform calculations, just like the processors you find everywhere from your smartphone to your smartwatch. The difference, however, is that quantum computers are much more powerful than classical computers. 

Classical computers encode information in binary bits. Computers use binary signals to process data. Data is represented as 1 or 0. A bit is a relatively simple state that represents one result or another, for example, a switch can be on or off. Sequences of 0s and 1s give us a lot of computing power. 

The longer the processing time, the more computing power is required. However, despite all the processing advances, traditional computing devices still face challenging tasks. Our current machines are inaccurate because electrons orbiting atoms are in superposition in the real world. 

Our current computers cannot calculate probabilities because electrons exist in more than one state at the same time. Quantum computers can take advantage of the fact that they operate using superposition. Superposition is a characteristic of subatomic particles such as electrons and photons that can exist in two different states at the same time.

-  The Challenge of Quantum Computing

One of the main problems facing quantum computers today is that entangled qubits quickly become incoherent relative to other qubits. Therefore, algorithms need to do their work quickly before the qubits become incoherent. 

Currently, most quantum computers can only keep a few dozen qubits coherent. A recent study showed that cosmic rays introduce a series of decoherence errors that are difficult to correct using standard error correction techniques.  This results in our inability to represent meaningful real-life problems on quantum computers. 

Also, there is no uniformity in the underlying quantum computing hardware. Currently, companies are looking at different ways to build quantum computers -- for example, Quantum Annealer, Analog Quantum Computer, and Universal Quantum Computer. This is very similar to our multiple transistor designs in the early days of computing. Therefore, only certain problems can be efficiently mapped onto specific types of underlying quantum computing hardware. 

Research is underway to solve the decoherence problem and design a universal quantum computer, and we are still about few years away from solving meaningful problems on a quantum computer. At the same time, we anticipate deploying quantum computers and classical computers in a hybrid fashion to provide computational efficiency.

- How Quantum Computers are Deployed

The promise of quantum computing is that it will help us solve certain types of problems that today's classical computers cannot solve in a reasonable amount of time."

Quantum computers require custom hardware; today, only large hyperscalers and a handful of hardware companies offer quantum computer simulators and quantum computers of limited size as cloud services. 

Quantum computers are currently targeting problems that are computationally intensive and latency-insensitive. Furthermore, today's quantum computer architectures are not mature enough to handle large amounts of data. Therefore, in many cases, quantum computers are often deployed in a hybrid fashion with classical computers. 

Although a quantum computer itself doesn't consume much power during computations, it requires specialized cryogenic refrigerators to keep superconducting temperatures low.

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