What exactly is quantum computing, and how does it operate? Quantum computing takes advantage of the perplexing behaviour that scientists ha...
What exactly is quantum computing, and how does it operate?
Quantum computing takes advantage of the perplexing behaviour that scientists have observed in nature's smallest particles - think atoms, photons, or electrons – for decades. The classical principles of physics no longer apply at this size, and we must instead rely on quantum rules.
While researchers may not know all about the quantum world, they do know that quantum particles have enormous potential, particularly the ability to contain and process massive amounts of information. Bringing those particles under control in a quantum computer might result in an explosion of computing capacity, which would exponentially improve innovation in many industries that require complicated computations, such as medicine development, climate modelling, financial optimization, and logistics.
What exactly is a quantum computer?
Quantum computers come in a variety of shapes and sizes, but they all operate on the same principle: they contain a quantum processor that isolates quantum particles for engineers to manipulate.
The nature of such quantum particles, as well as the technology used to manage them, vary depending on the quantum computing strategy. Some methods include cooling the CPU to freezing temperatures, while others involve playing with quantum particles using lasers - all with the purpose of determining how to best utilise the benefits of quantum physics.
What is the distinction between a quantum and a classical computer?
Classical computers are the systems that we have been utilising in many shapes and sizes since the 1940s - laptops, smartphones, cloud servers, and supercomputers. These are based on bits, which are units of information that power every computation in the device.
In a traditional computer, each bit can represent and convey information that is utilised to carry out computations by taking on a value of one or zero. Developers can write programmes, which are sets of instructions that are read and executed by the computer, using bits.
Classical computers have been important tools for decades, but the inflexibility of bits remains a limitation. As an example, if given the task of finding a needle in a haystack, a traditional computer would have to be programmed to go through every single piece of hay straw until it found the needle.
As a result, there are still many significant problems that traditional devices cannot handle. "There are calculations that could be done on a traditional system, but they may take millions of years or utilise more computer memory than the whole amount of computer memory on Earth," Sutor explains. "These issues are currently unsolvable."
How do quantum computers outperform traditional devices?
Qubits, also known as quantum bits, are at the heart of every quantum computer and can be loosely likened to the bits that process information in classical computers.
Qubits, on the other hand, have extremely different features than bits since they are made of quantum particles present in nature - the same particles that had scientists obsessed for many years.
One of the most useful qualities of quantum particles for quantum computing is superposition, which permits quantum particles to exist in several states at the same time. Superposition is best visualised by comparing it to flipping a coin: instead of heads or tails, quantum particles are the coin while it is still spinning.
Researchers can produce qubits by directing quantum particles and loading them with data — and because to superposition, a single qubit doesn't have to be either a one or a zero, but can be both at the same time. In other words, whereas a classical bit can only be heads or tails, a qubit can be both heads and tails at the same time.
This means that when a quantum computer is asked to solve a problem, it can employ qubits to conduct numerous calculations at once to discover an answer, exploring many potential routes in simultaneously.
So, in the needle-in-a-haystack example, a quantum computer, unlike a classical system, could theoretically browse through all hay straws at the same time, locating the needle in a matter of seconds rather than searching for years – even centuries – before finding what it was looking for.
Furthermore, due to another quantum phenomenon known as entanglement, qubits can be physically linked together, which means that with each qubit added to a system, the device's capabilities rise exponentially - whereas adding more bits only results in linear progress.
When we add another qubit in a quantum computer, we double the amount of information and processing power available for problem solving. So, by the time we reach 275 qubits, we will be able to compute with more information than there are atoms in the observable world. And the reduction in computation time that this could result in could have significant consequences in a variety of use scenarios.
What is the significance of quantum computing?
"In a variety of situations, time equals money. Being able to complete tasks more rapidly will have a significant influence on business "According to Scott Buchholz, managing director at Deloitte Consulting.
The time advantages anticipated by researchers as a result of quantum computing are not on the order of hours or even days. We're talking about potentially being able to tackle issues that today's most powerful supercomputers couldn't solve in thousands of years, from modelling hurricanes to cracking the cryptographic keys safeguarding the most sensitive government secrets, in a matter of minutes.
What is the purpose of a quantum computer?
Programmers create problems in the form of algorithms that classical computers can solve – and quantum computers will perform computations based on quantum algorithms. Some quantum algorithms have already been identified as being particularly appropriate to the improved capabilities of quantum computers by researchers.
Quantum systems, for example, might address optimization algorithms, which aid in identifying the optimal solution among many viable possibilities and could be implemented in a variety of scenarios ranging from supply chain administration to traffic control. ExxonMobil and IBM, for example, are collaborating to develop quantum algorithms that will one day handle the 50,000 merchant ships that sail the oceans every day to transport products, reducing the distance and time travelled by fleets.
Quantum simulation algorithms are also predicted to produce unprecedented findings, as qubits allow researchers to simulate and predict complicated interactions between molecules in bigger systems, potentially leading to faster advances in fields such as materials science and drug discovery.
AI and machine-learning applications stand to benefit greatly from quantum computers' ability to handle and interpret far larger datasets, with faster training times and more capable algorithms. Furthermore, researchers have proved that quantum algorithms have the ability to shatter traditional cryptography keys, which are now too mathematically tough for classical computers to crack.
What are the various kinds of quantum computers?
Scientists must identify and manipulate the smallest particles of nature — minuscule portions of the universe that can be found through various methods – in order to make qubits, which are the building blocks of quantum computers. As a result, many different types of quantum processors are now being developed by a variety of companies.
One of the most advanced ways involves the use of superconducting qubits, which are formed of electrons and resemble the familiar chandelier-like quantum computers. IBM and Google have both created superconducting CPUs.
Trapped ions is another solution that is gaining traction, with Honeywell and IonQ leading the way, in which qubits are contained in arrays of ions trapped in electric fields and then manipulated using lasers.
For their part, major corporations such as Xanadu and PsiQuantum are investing in yet another technology that uses quantum particles of light known as photons to encode data and create qubits. Qubits can be made from silicon spin qubits, which Intel is focused on, as well as cold atoms or even diamonds.
D-approach, Wave's quantum annealing, falls into a separate category of computing entirely. It does not use the gate model, which is used by other quantum processors. Because quantum annealing processors are significantly easier to manage and operate, D-Wave has already produced devices that can manipulate hundreds of qubits, whereas almost every other quantum hardware startup is working with 100 qubits or less. The annealing approach, on the other hand, is limited to a specific set of optimization issues, which limits its potential.
What can a quantum computer achieve today?
With only 100 qubits as the current state of the art, there is very little that can be done with quantum computers. Qubits will need to be counted in the thousands, if not millions, before they can do useful calculations.
"While there is a lot of promise and enthusiasm about what quantum computers can achieve one day," adds Buchholz, "I think what they can do today is very unimpressive."
Increasing the qubit count in gate-model processors, on the other hand, is extremely difficult. This is because it is difficult to retain the particles that make up qubits in their quantum state — similar to trying to keep a coin spinning without falling on one side or the other, but much more difficult.
To keep qubits spinning, they must be isolated from any external disturbance that could cause them to lose their quantum state. Google and IBM, for example, do this by cooling their superconducting processors to temperatures lower than space, which necessitates specialised cryogenic technologies that are currently near-impossible to scale up.
Furthermore, because qubits are unstable, they are unreliable and are still prone to causing computation errors. As a result, a branch of quantum computing has emerged dedicated to creating error-correction technologies.
Despite rapid progress in research, quantum computers are still locked in what is known as the NISQ era: noisy, intermediate-scale quantum computing – but the ultimate goal is to develop a fault-tolerant, universal quantum computer.
As Buchholz argues, it is difficult to predict when this may occur. "I'd assume we're a few years away from industrial use cases," he says, "but the real challenge is that this is a little like trying to predict scientific discoveries." "It's difficult to place a time limit on genius."
What exactly is quantum supremacy?
In 2019, Google announced that its 54-qubit superconducting processor named Sycamore had achieved quantum supremacy — the point at which a quantum computer can accomplish a computing problem that a classical device cannot solve in any reasonable period of time.
Google claims that Sycamore determined the solution to a problem that would have taken the world's most powerful supercomputers 10,000 years to solve in only 200 seconds.
Recently, researchers from China's University of Science and Technology made a similar achievement, claiming that their quantum processor completed a work that would have taken 600 million years to complete with classical equipment in 200 seconds.
This is not to suggest that either of those quantum computers can presently outperform any classical computer at any work. In both cases, the devices were programmed to perform very narrow tasks, with no utility other than demonstrating that they could perform the task substantially faster than traditional systems.
Without a higher qubit count and improved error correction, achieving quantum supremacy for meaningful applications remains a long-term goal.
What are quantum computers good for now?
Organizations investing in quantum resources perceive this as a stage of preparation: their scientists are laying the framework for the day when a universal and fault-tolerant quantum computer is ready.
In reality, this implies that they are attempting to identify the quantum algorithms that are most likely to outperform classical algorithms when performed on large-scale quantum systems. To that end, researchers typically attempt to demonstrate that quantum algorithms perform comparably to classical ones on very small use cases, with the theory that as quantum hardware improves and the size of the problem can be increased, the quantum approach will inevitably show some significant speed-ups.
Scientists at the Japanese steelmaker Nippon Steel, for example, recently developed a quantum optimization method that might compete with its classical counterpart for a modest issue run on a 10-qubit quantum computer. In theory, this means that the same algorithm with hundreds or millions of error-corrected qubits might eventually optimise the company's whole supply chain, including the management of dozens of raw materials, procedures, and tight deadlines, resulting in massive cost savings.
As a result, the work that quantum scientists are doing for businesses is very experimental, and there are now less than 100 quantum algorithms that have been proved to compete against their classical counterparts - highlighting how new the field is.
Who will win the race to quantum computing?
With most use cases requiring a fully error-corrected quantum computer, the question on everyone's lips in the quantum sector is who will produce one first, and the exact answer is unknown.
Every quantum hardware company is keen to emphasise that their technique will be the first to crack the quantum revolution, making it even more difficult to distinguish noise from reality. "Right now, it's like looking at a bunch of children at a playground and trying to figure out which one of them is going to win the Nobel Prize," Buchholz adds.
"I've heard the brightest minds in the area admit that they're not sure which of these is the correct answer. There are more than a half-dozen competing technologies, and it's still unclear which one will be the greatest, or if there will be one at all "He goes on.
Experts generally agree that the technology will not achieve its full potential until far after 2030. However, when error correction improves and qubit counts approach numbers that allow for minor issues to be coded, the next five years may bring some early application cases.
IBM is one of the few businesses that has committed to a particular quantum roadmap, including the eventual goal of creating a million-qubit quantum computer. In the near future, Big Blue expects to deliver a 1,121-qubit system in 2023, which might represent the beginning of the first experiments with real-world use cases.
What about quantum computing software?
Creating quantum hardware is a key element of the task, and it is arguably the most significant bottleneck in the ecosystem. However, even a universally fault-tolerant quantum computer would be useless without the corresponding quantum software.
"Of course, none of these online facilities are much use unless you know how to'speak' quantum," Andrew Fearnside, senior associate at intellectual property company Mewburn Ellis specialised in quantum technology.
It is not as simple as taking a conventional algorithm and applying it to the quantum realm to create quantum algorithms. Quantum computing, on the other hand, necessitates a completely new programming paradigm that can only be run on a completely new software stack.
Of course, several hardware vendors create software tools as well, the most well-known of which is IBM's open-source quantum software development kit Qiskit. On top of that, the quantum ecosystem is growing to include companies devoted solely to the development of quantum software. Zapata, QC Ware, and 1QBit are all well-known companies that specialise in providing businesses with tools to comprehend quantum physics.
In addition, promising partnerships are arising to bring together various sectors of the ecosystem. The recent collaboration between Honeywell, which is developing trapped ions quantum computers, and quantum software startup Cambridge Quantum Computing (CQC), for example, has analysts anticipating that a new participant will take the lead in the quantum race.
What exactly is quantum computing in the cloud?
Because of the intricacy of developing a quantum computer – think ultra-high vacuum chambers, cryogenic control systems, and other exotic quantum instruments – the vast majority of quantum systems are now confined to lab conditions rather than being shipped to customers' data centres.
To enable users to gain access to the devices and begin executing their experiments, quantum businesses have created commercial quantum computing cloud services, making the technology available to a broader variety of clients.
The four main public cloud computing service providers presently allow access to quantum computers on their platforms. IBM and Google have already deployed their own quantum processors in the cloud, while Microsoft's Azure Quantum and AWS's Braket services allow clients to connect to computers from third-party quantum hardware vendors.
What is the current state of the quantum computing industry?
The jury is still out on which technology, if any, will win the race, but one thing is certain: the quantum computing sector is growing quickly, and investors are generously backing the ecosystem. Equity investments in quantum computing nearly tripled in 2020, and according to BCG, they are expected to triple again in 2021, reaching $800 million.
Government investment is considerably greater: the United States has set aside $1.2 billion over the next five years for quantum information research, while the European Union has declared a €1 billion ($1.20 billion) quantum flagship. The United Kingdom just passed the £1 billion ($1.37 billion) budget milestone for quantum technology, and while official figures are not available in China, the government has made no secret of its desire to participate aggressively in the quantum race.
As a result, the quantum ecosystem has grown in recent years, with new firms expanding from a handful in 2013 to almost 200 by 2020. The appeal of quantum computing is also growing among potential customers: according to Gartner, whereas only 1% of organisations budgeted for quantum in 2018, 20% are predicted to do so by 2023.
Who is preparing for the quantum era right now?
Although not all firms must prepare to compete with quantum-ready competitors, there are particular industries where quantum algorithms are predicted to provide significant value and where leading organisations are actively prepared.
Goldman Sachs and JP Morgan are two financial behemoths that have invested in quantum computing. This is because quantum optimization algorithms in banking could improve portfolio optimization by better determining which stocks to buy and sell for maximum profit.
In pharmaceuticals, where drug development is typically a $2 billion, 10-year process based primarily on trial and error, quantum simulation algorithms are expected to create waves. This is also true in materials science, where businesses such as OTI Lumionics are investigating the use of quantum computers to develop more efficient OLED displays.
Leading automotive companies such as Volkswagen and BMW are also keeping a close eye on the technology, which has the potential to impact the sector in a variety of ways, ranging from creating more efficient batteries to improving the supply chain to improved traffic and mobility management. Volkswagen, for example, was a pioneer in the application of a quantum algorithm to optimise bus routes in real time while avoiding traffic bottlenecks.
However, as the technology advances, it is unlikely that quantum computing would be limited to a select few. Rather, analysts believe that almost all industries will profit from the processing speedup that qubits will enable.
Will quantum computers eventually replace laptop computers?
Quantum computers are projected to be amazing at tackling a specific class of problems, but this does not imply that they will be a superior tool than conventional computers for every application. Quantum systems, in particular, are unsuitable for fundamental computations such as arithmetic or command execution.
"Quantum computers are excellent constraint optimizers, but they are not required to operate Microsoft Excel or Office," explains Buchholz. "That's what traditional technology is for: doing a lot of math, calculations, and sequential operations."
In other words, the way we compute now will always have a place. It is improbable that you will be able to watch a Netflix series on a quantum computer very soon. Rather, the two technologies will be utilised in tandem, with quantum computers being employed only when they can substantially speed up a certain task.
What will we do with quantum computers?
Buchholz believes that once classical and quantum computing begin to coexist, access will appear as a configuration option. Data scientists presently have the option of running their workloads on CPUs or GPUs, and quantum processing units (QPUs) may be added to the list at some time. Researchers will have to determine which configuration to use based on the nature of their computation.
Although the particular method by which consumers will access quantum computing in the future is unknown, one thing is certain: they will not be required to comprehend the fundamental laws of quantum computing in order to use the technology.
"People are perplexed because we introduce quantum computing by discussing technical aspects," explains Buchholz. "However, you do not need to comprehend how your cellphone works in order to use it." People sometimes forget that when they join into a server somewhere, they have no notion where the server is physically or even if it exists physically at all. The crucial question is what it will look like to gain access to it."
And, as fascinating as qubits, superposition, entanglement, and other quantum phenomena are, most of us will be relieved.
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