Quantum Computing

Uploaded on 2023-11-06 in TECHNOLOGY--Developments, Education & Research

Quantum Computing - Its Background & Future

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Digital computers have been making it easier for us to process information for decades, but now quantum computers are ready to take us and computing to a whole new level. Quantum computers won’t replace today’s computers, but they will be able to solve very complex statistical problems that current computers can not solve.

Quantum computing uses the principles of quantum theory that explains the behavior of energy and material on the atomic and subatomic levels.

Like a classical computer, a quantum computer operates on bits. However, while classical bits can only be found in the states 0 and 1, a quantum bit, or qubit, can represent the values 0 and 1, or linear combinations of both and these linear combinations are known as superpositions, or superposition states.

Current Computing and Now Quantum Computing

Let’s consider the basics. Classical computers today employ a stream of electrical impulses (1 and 0) in a binary manner to encode information in bits. This restricts their processing ability, compared to quantum computing.

A quantum computer is a computer that takes advantage of quantum mechanic phenomena.

Quantum computing uses subatomic particles, such as electrons or photons. Quantum bits, or qubits, allow these particles to exist in more than one state (i.e., 1 and 0) at the same time. Theoretically, linked qubits can exploit the interference between their wave-like quantum states to perform calculations that might otherwise take millions of years.

Today’s classical computers are straightforward. They work with a limited set of inputs and use an algorithm and spit out an answer, and the bits that encode the inputs do not share information about one another. Quantum computers are different.

For one thing, when data are input into the qubits, the qubits interact with other qubits, allowing for many different calculations to be done simultaneously. This is why quantum computers are able to work so much faster than classical computers. But that’s not the end of the story: quantum computers don’t deliver one clear answer like classical computers do; rather, they deliver a range of possible answers.

Quantum computing has the capability to sift through huge numbers of possibilities and extract potential solutions to complex problems and challenges.

Such massive computing potential and the projected market size for its use have attracted the attention of some of the most prominent companies. These include IBM, Microsoft, Google, D-Waves Systems, Alibaba, Nokia, Intel, Airbus, HP, Toshiba, Mitsubishi, SK Telecom, NEC, Raytheon, Lockheed Martin, Rigetti, Biogen, Volkswagen, and Amgen.

Background

At small scales, physical matter exhibits properties of both particles and waves, and quantum computing leverages this behavior, specifically quantum superposition and entanglement, using specialised hardware that supports the preparation and manipulation of quantum states.

Classical physics cannot explain the operation of these quantum devices, and a scalable quantum computer could perform some calculations exponentially faster than any modern classical computer. In particular, a large-scale quantum computer could break widely used encryption schemes and aid physicists in performing physical simulations.

The basic unit of information in quantum computing is the qubit, similar to the bit in traditional digital electronics. Unlike a classical bit, a qubit can exist in a super-position of its two "basis" states, which loosely means that it is in both states simultaneously.

When measuring a qubit, the result is a probabilistic output of a classical bit, therefore making quantum computers nondeterministic in general. If a quantum computer manipulates the qubit in a particular way, wave interference effects can amplify the desired measurement results. The design of quantum algorithms involves creating procedures that allow a quantum computer to perform calculations efficiently and quickly.

In recent years, large companies have been taking important steps forward in quantum computing, which looks set to revolutionise the world as we know it.

Scientists and engineers anticipate that certain problems that are effectively impossible for conventional, classical computers to solve will be easy for quantum computers Quantum computing is a multi-disciplinary field comprising aspects of computer science, physics, and mathematics that uses quantum mechanics to solve complex problems faster than on classical computers. The field of quantum computing includes hardware research and application development.

This new generation of super-computers uses knowledge of quantum mechanics, this is the area of physics that studies atomic and subatomic particles, to overcome the limitations of classic computing.

Although in practice, quantum computing faces evident problems regarding scalability and incoherence, it makes it possible to perform multiple simultaneous operations and eliminates the tunnel effect that limits current nanometric scale programming.

Quantum Computer Problem Solving

Quantum computers are able to solve certain types of problems faster than classical computers by taking advantage of quantum mechanical effects, such as superposition and quantum interference.
Some applications where quantum computers can provide such a speed boost include machine learning (ML), optimisation, and simulation of physical systems.

Eventual use cases could be portfolio optimisation in finance or the simulation of chemical systems, solving problems that are currently impossible for even the most powerful supercomputers on the market.

Quantum mechanics is the area of physics that studies the behaviour of particles at a microscopic level. At subatomic levels, the equations that describe how particles behave is different from those that describe the macroscopic world around us.

Quantum computers take advantage of these behaviours to perform computations in a completely new way.

Nascent quantum computers have existed in various forms more than a decade. Several technology companies already have working quantum computers and use them with related programming languages and software development resources.

The technology with the broadest potential uses, in which quantum gates control qubits through logical operations, is in fast-moving, early development. Today, computers of this type generally have fewer than 100 qubits. The qubits are kept in a quantum state inside nested chambers that chill them to near absolute zero temperature and shield them from magnetic and electric interference.

This technology became significant in 2019, when a quantum computer completed a specific calculation in a sliver of the time a classical supercomputer would have needed to solve the same problem. The feat is considered a proof of principle; the use of this type of quantum computer to solve practical problems is expected to be years away.

It may be years before general-purpose quantum computers can be applied to a variety of practical problems. To do useful work, they probably will require thousands of qubits. Scaling up brings challenges.

Large numbers of qubits are harder to isolate, and if they interact with molecules or magnetic fields in their environment, they collapse or decohere, losing the essential but fragile properties of superposition and entanglement. The more qubits there are, the more likely the machine is to make errors as individual qubits are disturbed by the environment.

Theorists and experimentalists develop strategies to reduce errors, lengthen the time that qubits can stay in quantum states, and increase the system's fault tolerance, preserving its accuracy even in the presence of errors.

Researchers are inventing new designs for qubits and quantum computers and enhancing existing technology. Established and newer strategies will take time to scale up, increase reliability, and demonstrate their potential.

The History of Quantum Computing

The prehistory of quantum computing begins early in the 20th century, when physicists began to sense they had lost their grip on reality.

Quantum Leaps:

1980: Physicist Paul Benioff suggests quantum mechanics could be used for computation.

1981: Nobel-winning physicist Richard Feynman at Caltech, coins the term quantum computer.

1985: Physicist David Deutsch at Oxford, maps out how a quantum computer would operate, a blueprint that underpins the nascent industry of today.

1994: Mathematician Peter Shor, at Bell Labs, writes an algorithm that could tap a quantum computer’s power to break widely used forms of encryption.

2004: Barbara Terhal and David DiVincenzo, two physicists working at IBM, developed theoretical proofs showing that quantum computers can solve certain math puzzles faster than classical computers.

2014: Google starts its new quantum hardware lab and hires the professor behind some of the best quantum computer hardware.

2014: Google hires the professor behind some of the best quantum computer hardware.

2016: IBM puts some of its prototype quantum processors on the Internet for anyone to experiment with, saying programmers need to get ready to write quantum code.

2019: Google’s quantum computer beats a classical super-computer at a commercially useless task based on Terhal and DiVincenzo’s 2004 proofs, in a feat many call “quantum advantage.”

2020: The University of New South Wales in Australia offers the first undergraduate degree in quantum engineering to train a workforce for the budding industry.

Initially, the generally accepted explanations of the subatomic world turned out to be incomplete. Electrons and other particles didn’t just neatly carom around like Newtonian billiard balls, for example. Sometimes they acted like a wave instead.

Quantum mechanics emerged to explain such anolalies, but introduced otherquestions. To take just one brow-wrinkling example, this new math implied that physical properties of the subatomic world, like the position of an electron, existed as probabilities before they were observed.

Before you measure an electron’s location, it is neither in one place nor another, but some probability of everywhere. This can be compared to tossing a coin - before it lands, the quarter is neither heads nor tails, but some probability of both.

A year before winning a Nobel Prize for his contributions to quantum theory, Richard Feynman said “nobody understands quantum mechanics.” The way we experience the world just isn’t compatible. But some people grasped it well enough to redefine our understanding of the universe. And in the 1980s, a few of them, including Feynman, began to wonder whether quantum phenomena like subatomic particles' probabilistic existence could be used to process information.

The basic theory or blueprint for quantum computers that took shape in the ’80s and ’90s still guides Google and other companies working on the technology.

Smartwatches, iPhones, and the world’s fastest super-computer all basically perform the task: They perform calculations by encoding information as digital bits, 0s and 1s. A computer might flip the voltage in a circuit on and off to represent 1s and 0s. In contrast, Quantum computers do calculations using bits, too. After all, we want them to plug into our existing data and computers. But quantum bits, or qubits, have unique and powerful properties that allow a group of them to do much more than an equivalent number of conventional bits.

Qubits can be built in various ways, but they all represent digital 0s and 1s using the quantum properties of something that can be controlled electronically. Popular examples, at least among a very select slice of humanity, include superconducting circuits, or individual atoms levitated inside electromagnetic fields.

The unprecedented power of quantum computing is that this arrangement lets qubits do more than just flip between 0 and 1. Treat them right and they can flip into a mysterious extra mode called a superposition.

Quantum Computing's Future

Quantum computing has the potential to drive the major breakthroughs needed to help solve the climate crisis. A pioneer in the field discusses how his company is seeking to harness this technology for large-scale climate-change mitigation. According to industry trade publication The Quantum Insider, there are more than 600 companies and more than 30 national labs and government agencies worldwide that are developing quantum computing technology.

This includes US-based tech giants such as Amazon, Google, Hewlett Packard Enterprise, Hitachi, IBM, Intel and Microsoft as well as Massachusetts Institute of Technology, Oxford University and the Los Alamos National Laboratory. Other countries, including the UK, Australia, Canada, China, Germany, Israel, Japan and Russia, have made significant investments in quantum computing technologies.

Britain has recently launched a government-funded quantum computing program. In 2020, the Indian government introduced its National Mission on Quantum Technologies & Applications. Here are some potential benefits of quantum computing:

Financial institutions may be able to use quantum computing to design more effective and efficient investment portfolios for retail and institutional clients. They could focus on creating better trading simulators and improve fraud detection.

The healthcare industry could use quantum computing to develop new drugs and genetically-targeted medical care. It could also power more advanced DNA research.

For stronger online security, quantum computing can help design better data encryption and ways to use light signals to detect intruders in the system.

Quantum computing can be used to design more efficient, safer aircraft and traffic planning systems.

Conclusion

Quantum computing is a rapidly developing field that will change computing and solve some of the world’s most complex problems. And the property of qubits makes quantum computers perform certain calculations exponentially faster than classical computers.

Despite the promise of quantum computing, there are still significant challenges that must be overcome before it can be widely adopted.

One of the largest problems is developing error-correcting codes that can protect quantum information from the effects of noise and decoherence. Another challenge is building quantum computers with enough qubits to solve meaningful problems.

Overall, the field of quantum computing is still in its early stages, but it has the potential to fundamentally transform computing and solve problems that are currently intractable with classical computers. As research progresses, we will see significant advancements in both the theory and practical applications of quantum computing.

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