Quantum computers: Eight ways quantum computing is going to change the world

Quantum computers are poised to bring about a revolution in computing, attracting the attention and investment of major companies and governments worldwide. While still in their early stages, these powerful machines have the potential to overcome the limitations of classical computers and solve complex problems in minutes that would take years or even centuries for traditional systems to complete. This article explores eight key areas where quantum computing is expected to make a significant impact, potentially transforming entire industries.

One area where quantum computers could revolutionize is drug discovery. The process of creating new drugs involves modeling complex interactions between particles in molecules, requiring massive computational power. Quantum computers, with their ability to perform multiple calculations simultaneously, could simulate these interactions and identify potential drug candidates much faster than current methods. Pharmaceutical companies are taking notice, with healthcare giant Roche partnering with Cambridge Quantum Computing (CQC) to explore the possibilities. Startups like Menten AI are also leveraging quantum algorithms to design new therapeutic proteins.

Another field that could benefit from quantum computing is battery technology. As the demand for batteries increases, researchers are searching for materials with better properties to improve their capacity and charging speed. Quantum computers are well-suited for modeling the behavior of molecules and could help identify promising battery materials. German car manufacturer Daimler is already using quantum computers to simulate the behavior of sulfur molecules and develop better lithium-sulfur batteries.

Quantum computers may also have a significant impact on weather prediction. While current supercomputers provide substantial computing power, they struggle to process the vast amount of data required for accurate long-range weather forecasts. Quantum computers, capable of analyzing multiple environmental factors simultaneously, could generate highly accurate predictions. The European Centre for Medium-Range Weather Forecasts (ECMWF) has partnered with Atos to explore the potential of quantum computing in weather and climate prediction.

In the financial sector, quantum computers offer the potential to improve banking operations. One application showing promise is the use of quantum computing in Monte Carlo simulations, which are used to predict market behavior. Quantum computers’ computational power could significantly accelerate these calculations, providing more accurate predictions and enhancing risk assessment. Companies like JP Morgan, Goldman Sachs, and Wells Fargo are actively investigating the potential of quantum computing in finance.

Language processing is another area where quantum computing could excel. Traditional natural language processing algorithms struggle to interpret the meaning of complex sentences. Quantum natural language processing (QNLP) aims to represent language as a network, enabling more intuitive processing. Cambridge Quantum Computing (CQC) has developed tools and software for QNLP, allowing sentences to be converted into quantum circuits.

The traveling salesman problem, a common optimization challenge faced by companies, could benefit from quantum computing. As the number of destinations increases, the problem becomes too complex for classical computers to solve efficiently. Quantum computers’ ability to explore multiple routes simultaneously could help find optimal solutions for supply chain optimization. Energy giant ExxonMobil has partnered with IBM to tackle this problem and has seen promising results with quantum algorithms.

Traffic congestion is a pervasive problem in cities worldwide, and quantum computing could offer a solution. Optimizing traffic signals to adapt to changing conditions and reduce congestion is a computationally intensive task. Quantum computers’ parallel computing capabilities could assess different scenarios simultaneously, leading to more efficient traffic management. Microsoft, Toyota Tsusho, and startup Jij are collaborating on quantum-inspired algorithms to reduce congestion in simulated city environments.

Lastly, quantum computing has the potential to enhance data security. Classical cryptographic algorithms are vulnerable to attacks as computers become more powerful. Quantum behavior, characterized by randomness, can be harnessed to generate encryption keys that are impossible to reverse-engineer. Startups like Nu Quantum are already working on commercializing quantum random number generation for stronger cryptography.

In conclusion, quantum computing holds immense promise in transforming various industries. From revolutionizing drug discovery and battery technology to improving weather prediction, finance, language processing, optimization problems, traffic management, and data security, the potential applications are vast. While quantum computers are still developing, their future impact on the world of computing is undeniable.

Source: https://www.zdnet.com/article/quantum-computers-eight-ways-quantum-computing-is-going-to-change-the-world/

How Quantum Computing Will Change the World

Quantum computing is rapidly becoming a reality, and many companies are eagerly awaiting its potential benefits. Governments and companies worldwide, including Google, Microsoft, and Intel, are investing heavily in quantum technology research and development. As entrepreneurs and executives, it is our responsibility to educate ourselves about these machines and their potential consequences. Understanding quantum computing is crucial if we want to leverage it for our organizations’ long-term advantage.

Quantum mechanics, the study of tiny particles like atoms and molecules, forms the foundation of quantum computing. Researchers are exploring ways to manipulate quantum behaviors to advance the field and develop new applications. Quantum sensors, quantum computers, and quantum security have emerged as promising technologies with tremendous potential. Quantum computers can perform high-speed and accurate molecular simulations, aiding the discovery of new materials, drugs, and more.

Quantum computing differs from classical computing by using qubits instead of bits. Qubits can exist in multiple states simultaneously, allowing quantum computers to perform many calculations simultaneously and exponentially increase their processing power. Quantum computers excel at solving complex problems that are beyond the capabilities of classical computers.

There are two main problems that quantum computing can help solve. First is optimization, where finding the best solution from numerous possibilities becomes challenging. Quantum computers can handle this task effectively. The second problem is simulation, where understanding how something works without physical access is crucial. Quantum computers can simulate complex systems like climate patterns, aiding in research and analysis.

The potential applications of quantum computing are vast. In the pharmaceutical industry, quantum computing can revolutionize drug discovery, design, and toxicity testing. It could reduce the time required to bring new drugs to the market and enable precision medicine. Quantum computing can also benefit the chemical industry by improving catalyst designs, leading to more efficient production processes and the use of sustainable substances.

The finance industry can leverage quantum computing for deeper analytics and faster trading. Major institutions like JPMorgan Chase are exploring quantum technology’s potential, partnering with companies like IBM. Quantum computing offers nearly limitless business potential, enabling innovation, improved supply chain management, and better customer service strategies.

Quantum computing can provide three main business benefits: revenue increase, cost reduction, and infrastructure savings. By analyzing data more quickly and accurately, companies can identify marketing and sales opportunities and adjust their strategies accordingly. Quantum computing’s ability to solve large-scale optimization problems can optimize logistics, supply chains, and scheduling, improving resource management. It can also reduce operating costs and help businesses save on physical infrastructure.

In conclusion, quantum computing is set to change the world. It has the potential to accelerate research, optimize processes, and revolutionize industries such as pharmaceuticals, chemicals, and finance. However, it is essential to address the challenges posed by quantum computing, such as post-quantum encryption to protect against data theft. Embracing quantum computing and understanding its implications will be crucial for companies to stay relevant and leverage its potential in the future.

Source: https://www.thedigitalspeaker.com/quantum-computing-change-world/

Quantum computers: what are they good for?

Quantum computers have long been hailed as the next revolution in computing, but so far, the reality has fallen short of the hype. While researchers have made progress, there are significant challenges that need to be overcome. However, there is growing optimism that the potential of quantum computers is becoming more plausible.

Winfried Hensinger, a physicist at the University of Sussex, has published a proof of principle for a large-scale, modular quantum computer. His start-up company, Universal Quantum, is now collaborating with Rolls-Royce and others to begin the process of building it. Despite the current limitations of quantum computers, researchers are surprising themselves with the progress they have made.

Quantum computers have the potential to accelerate drug discovery, enhance encryption cracking, improve financial transactions, advance machine learning, develop revolutionary materials, and even address climate change. While these claims may seem ambitious, computational mathematician Steve Brierley believes that the long-term potential of quantum computing is even greater than what is currently imagined.

One of the challenges in building quantum computers lies in the hardware itself. Quantum computers store data in quantum bits or qubits, which can be made using various technologies. These qubits must be robust against errors caused by thermal vibrations, cosmic rays, and electromagnetic interference. Additionally, useful computations require a large number of qubits that do not yet exist.

Despite these challenges, there is room for optimism. Researchers are exploring hardware breakthroughs that could overcome some of the obstacles, such as error mitigation and entanglement forging. These measures reduce errors in quantum computers and improve their performance. There is also ongoing research to optimize quantum algorithms for specific applications, resulting in significant gains in speed and efficiency.

IBM researchers have already demonstrated the potential of quantum computing in simulating the properties of molecules and improving lithography techniques. Quantum chemistry calculations and molecular reactions are expected to be the first commercial applications of quantum computing. Other potential areas for quantum computation include financial applications, materials science, logistics optimization, and even quantum versions of machine learning.

While there is still a long way to go before quantum computers reach their full potential, researchers and companies remain optimistic. They believe that a quantum-skilled workforce is crucial for the future of quantum computing. The road ahead may be slow and challenging, but with continued progress and innovation, quantum computers have the potential to revolutionize various fields and tackle complex problems that are currently beyond the reach of classical computers.

Source: https://www.nature.com/articles/d41586-023-01692-9

Explained: What is quantum computing and how will it change the world?

Quantum computing is an emerging field that has the potential to bring about significant changes in various sectors. These powerful devices, based on the principles of quantum mechanics, have the ability to solve complex problems and accelerate advancements in fields like drug discovery and materials science. Quantum computers operate on the basis of qubits, which are the basic units of information in quantum computing. Unlike classical computers that use bits with values of 0 or 1, qubits can be in a superposition state of both 0 and 1 simultaneously, exponentially increasing the computational power of quantum machines.

Entanglement is another crucial property of quantum computing. When two qubits are entangled, there is a correlation between their states, regardless of the distance between them. This phenomenon, which does not have an equivalent in classical computing, provides stronger connectivity between qubits and enhances the computational capabilities of quantum computers.

The potential applications of quantum computers are vast. They can aid in simulating and understanding the quantum world, leading to the design of new materials with specific properties. For example, quantum computers could help create more efficient batteries for electric vehicles or develop materials that facilitate effective CO2 capture, addressing challenges related to climate change. By simulating atoms and molecules, quantum computers can contribute to solving problems in energy storage, food production, and other critical areas.

However, alongside the benefits, there are concerns regarding the security of current encryption protocols. The extraordinary computational power of quantum computers poses a threat to the encryption methods used to secure data transmission over the internet. Algorithms like RSA and Diffie–Hellman, which rely on mathematical assumptions, could be broken by quantum computers. To address this issue, organizations and state actors are advised to update their cryptography to quantum-safe algorithms that cannot be compromised by quantum machines.

While it is essential to prepare for the potential risks associated with quantum computing, such as unauthorized decryption of existing data, the benefits outweigh these concerns. Quantum computers have the potential to revolutionize various fields, including medicine, by accelerating the discovery of chemical reactions and facilitating advancements in drug development. The negative side effects, such as breaking encryption, can be addressed through the development of quantum-safe algorithms.

In conclusion, quantum computing has the power to transform the world by solving complex problems and enabling significant advancements in various sectors. The ability of quantum machines to operate on qubits in superposition and utilize entanglement provides exponential computational power compared to classical computers. While challenges exist, such as the security of encryption protocols, the potential benefits of quantum computing outweigh the risks. By leveraging the capabilities of quantum computers, we can tackle critical issues like climate change, energy storage, and drug discovery, leading to a brighter future.

Source: https://www.euronews.com/next/2023/04/12/what-is-quantum-computing-and-what-does-a-quantum-computer-do

What is Quantum Computing? | IBM

Quantum computing is a revolutionary technology that utilizes quantum mechanical principles to perform computations. Unlike classical computers that use bits, which can represent either a 0 or a 1, quantum computers use qubits (CUE-bits) that can exist in a superposition of both 0 and 1 simultaneously. This allows quantum computers to perform complex calculations and solve problems that are currently intractable for classical computers.

One of the key challenges in quantum computing is maintaining the delicate quantum states of qubits. To overcome this, IBM uses superconducting qubits that operate at ultra-cold temperatures, just a fraction of a degree above absolute zero. At these temperatures, certain materials become superconductors, allowing electrons to flow through them without resistance. Superconductors, in combination with Josephson junctions, enable the control of qubits in IBM’s quantum processors.

Control of qubits is achieved by firing microwave photons at the Josephson junctions. This enables the manipulation and readout of individual units of quantum information. While a single qubit is not particularly useful, it can be placed in a state of superposition, representing all possible configurations simultaneously. When multiple qubits are entangled, changes to one qubit will directly affect the others, allowing for powerful computational capabilities.

Entangled qubits can be manipulated through interference, which refers to the interaction of waves of probabilities. In a quantum system with entangled qubits in a state of superposition, there are various possible outcomes of a measurement. Interference can cause certain outcomes to amplify while others cancel out, leading to the solution of a computation. By selectively applying interference through a quantum circuit, users can guide the computation to the desired solution.

Quantum computing has the potential to revolutionize fields such as cryptography, optimization, and drug discovery. Its ability to handle vast amounts of data and perform complex calculations can lead to breakthroughs in various scientific and technological domains. However, quantum computing is still in its early stages, and many challenges remain, such as improving qubit coherence, reducing errors, and scaling up the technology.

IBM is at the forefront of quantum computing research and development, continually working to advance the field. Their quantum processors, despite being housed on a wafer no larger than a laptop, require extensive cooling systems to maintain the ultra-cold temperatures necessary for quantum operations. As the technology progresses, the hope is to build larger and more powerful quantum hardware systems capable of tackling increasingly complex problems.

In conclusion, quantum computing leverages the principles of superposition, entanglement, and interference to perform computations that are beyond the reach of classical computers. By utilizing superconducting qubits and advanced control techniques, IBM is pushing the boundaries of this transformative technology, paving the way for a future where quantum computers can solve complex problems and drive innovation across various industries.

Source: https://www.ibm.com/topics/quantum-computing

What is quantum computing?

Quantum computing represents a new approach to computing that has the potential to solve complex statistical problems that classical computers cannot handle. While classical computers are based on bits that can store either a zero or a one, quantum computers use qubits that can simultaneously represent both zero and one, thanks to a property called superposition. This allows quantum computers to explore a massive number of paths simultaneously, making them potentially faster and more powerful than classical computers.

In 2019, Google made a breakthrough announcement when its quantum computer solved a problem in 200 seconds that would have taken a classical computer 10,000 years. However, this achievement was more of a theoretical leap forward rather than a practical one, as the problem had no real-world use. Nevertheless, we are approaching a time when quantum computers will have a real impact on our lives.

Quantum computers work differently from classical computers. When data is input into qubits, they interact with other qubits, allowing for multiple calculations to be done simultaneously. Unlike classical computers, quantum computers do not deliver one clear answer but rather a range of possible answers. While classical computers are still preferred for calculations with limited scope, quantum computers can save time by narrowing down the range of possible answers for complex problems.

The development of quantum computing faces several obstacles. One major challenge is the fragile nature of qubits. When a qubit changes its status, inputs can be lost or altered, affecting the accuracy of results. Additionally, a large-scale quantum computer capable of delivering significant breakthroughs will require millions of connected qubits, which is far beyond the capabilities of current quantum computers.

In the near future, classical and quantum computers are expected to work together, with quantum computing assisting classical computing in solving multivariable problems. Quantum computers can help narrow down the range of possible solutions, aiding companies in reaching optimal solutions faster.

Quantum computing has potential business use cases in various industries. Experts believe it can eventually model complex molecules in the human body, benefiting fields like healthcare and pharmaceuticals. Other industries such as finance, logistics, and cryptography can also benefit from the power of quantum computing.

Apart from quantum computing, there are other quantum technologies to explore. Quantum communication (QComms) enables strong encryption protocols that enhance information security, while quantum sensing (QS) allows for more accurate measurements of physical properties like temperature, magnetic fields, and rotation. Although quantum computing has received most of the attention and funding, QComms and QS are expected to gain significant interest and funding in the future.

One major challenge organizations face is the shortage of quantum professionals to meet the demand for quantum computing. The talent gap could hinder the potential value creation estimated at $1.3 trillion. Lessons from the AI talent journey can help organizations build the necessary quantum talent, and addressing this issue is crucial for organizations to capture the value that quantum computing can bring.

In summary, quantum computing represents a paradigm shift in computing, offering the potential to solve complex problems that classical computers cannot handle. Although quantum computers are not yet widely available, they are expected to have a significant impact on various industries in the future. Quantum communication and sensing are also promising quantum technologies. However, organizations need to address the talent gap to fully leverage the potential of quantum computing.

Source: https://www.mckinsey.com/featured-insights/mckinsey-explainers/what-is-quantum-computing

What Can a Quantum Computer Actually Do? – Qiskit – Medium

Quantum computers have garnered significant attention for their potential to solve complex problems that are beyond the reach of classical computers. However, understanding the precise capabilities of quantum computers and how they compare to classical computers is a complex matter. To delve into this topic, it’s essential to explore computational complexity theory, specifically the class of problems that quantum computers can easily solve known as BQP (bounded-error quantum polynomial time).

Classical computers, which operate using logic operations on bits (units that can take on one of two states), are capable of solving problems in P (Polynomial Time). P represents problem types that can be solved by a classical computer with polynomial time resources. While problems in P are theoretically solvable, their polynomial factor can still be extremely large, making them challenging in practice. Examples of problems in P include multiplication.

NP (Nondeterministic Polynomial Time) is a complexity class that encompasses problems for which a deterministic Turing machine can check a solution’s correctness in polynomial time. NP includes all of P and problem types for which it’s uncertain whether a polynomial time solution exists. NP-Hard refers to problem types that are at least as hard as the hardest problems in NP. NP-Complete represents the intersection of NP and NP-Hard, including problem types that are in NP. If a polynomial time solution is found for any NP-Complete problem, it would imply that P=NP, which is not expected to happen.

Moving on to quantum computing, BPP (Bounded-Error Probabilistic Polynomial Time) allows randomness as a resource to solve problems in polynomial time. BQP (Bounded-Error Quantum Polynomial Time) is the class of problems that quantum computers, with their additional capabilities of superposition, entanglement, and interference, can solve in polynomial time with a limited amount of error. Quantum computers can solve problems in P and BPP, as well as some NP problems like factoring using Shor’s algorithm. However, it’s unclear whether they can efficiently solve problems in the NP-Complete class.

BQP lies between BPP and PP (Probabilistic Polynomial Time), and its boundaries are not precisely defined. While BQP is more powerful than BPP, it’s important to note that the relationship between complexity classes such as P, NP, and PH (Polynomial Hierarchy) is still not completely understood. The computational value that quantum computers offer often depends on the unresolved question of whether P is equal to NP.

Despite these uncertainties, research has shown core advantages in computing with quantum bits over classical bits. Quantum scratch space has been proven to be inherently more powerful than classical scratch space. Moreover, BQP offers solutions to problem types outside of NP, although further exploration is needed to determine their practical value. Hardware developers are actively working on creating error-corrected quantum processors capable of running these algorithms.

In summary, while the precise capabilities of quantum computers are not fully clear and depend on the development of powerful hardware, we know that they can efficiently solve problems that are currently intractable for classical computers. The separation between quantum and classical computers exists, and BQP encompasses polynomial solutions even for problems outside of NP. With ongoing research and advancements in hardware, we hope to unlock further advantages offered by quantum computing.

Source: https://medium.com/qiskit/what-can-a-quantum-computer-actually-do-4daed0691f6b

10 Quantum Computing Applications and Examples

Google made headlines in October 2019 when it announced a breakthrough in quantum computing called quantum supremacy. This achievement means that a quantum computer can perform tasks that a conventional computer cannot complete in a reasonable amount of time. IBM, another major player in the quantum computing field, disagreed with Google’s claim and argued that their supercomputers still had significant computing power. Despite this debate, Google’s achievement marked a milestone in quantum computing’s development and sparked interest in its potential applications.

Before quantum computing can reach its full potential, researchers need to overcome several challenges. One of the main hurdles is increasing the number of qubits, the units of information in quantum computers. Unlike classical computer bits that represent either 1 or 0, qubits can represent both simultaneously. This property allows for significantly faster processing speeds, which are crucial for simulating complex quantum mechanics at the molecular level.

While quantum computing is still in its early stages, experts predict various applications for this technology. One potential application is in the field of machine learning. Quantum computers could improve our understanding of quantum mechanics and surpass classical computers in data pattern recognition tasks. IBM’s research demonstrated that entangling qubits reduced the error rate in a data-classification experiment compared to unentangled qubits. This suggests that as quantum computers improve in harnessing and entangling qubits, they will become better at tackling machine learning problems.

The finance industry is also exploring the potential of quantum computing. Companies like NatWest and Willis Towers Watson, both part of Microsoft’s Quantum Network, are interested in leveraging quantum technology for financial modeling. Quantum computers could accelerate or improve machine learning in finance, leading to more accurate risk assessment and other advancements.

Quantum computing could also revolutionize the field of weather prediction. The ability of quantum computers to perform simultaneous calculations makes them suitable for analyzing the complex variables involved in weather systems. While current supercomputers are used for weather modeling, accurate numerical weather prediction remains challenging. Quantum computing’s unique capabilities may offer new possibilities for more accurate weather forecasts.

Cybersecurity is another area where quantum computing has significant implications. The immense computing power of quantum computers could potentially break current encryption systems, posing a threat to cybersecurity. To address this, the security community is actively developing quantum-resistant encryption algorithms. British-based cybersecurity leader Post-Quantum has developed one of the algorithms that made it to the semifinals of the National Institute of Standards and Technology’s competition. The process of developing quantum-resistant encryption requires careful consideration to avoid transitioning to new algorithms either too soon or too late.

Quantum computing’s ability to simulate molecular processes opens up possibilities for advancements in pharmaceutical research. Toronto-based biotech startup ProteinQure is partnering with quantum computing leaders like IBM, Microsoft, and Rigetti Computing, as well as pharmaceutical research institutions, to explore the potential of quantum computing in modeling protein behavior. Quantum computers could accelerate the development of targeted drugs for diseases like cancer, Alzheimer’s, and heart disease.

Other industries are also exploring the benefits of quantum computing. Automakers like Daimler and Volkswagen are partnering with quantum computing powerhouses Google, IBM, and D-Wave Systems to improve car battery technology, optimize traffic flows, and accelerate logistics. Quantum computing’s ability to solve optimization problems, such as the traveling salesman problem, could lead to significant improvements in various fields. Additionally, quantum computing has the potential to enhance hydrogen fuel production, aiding in the search for sustainable energy alternatives.

Overall, while quantum computing is still in its early stages, its potential applications are vast and promising. From machine learning and finance to weather prediction, cybersecurity, drug development, automotive technology, and sustainable energy, quantum computing has the potential to revolutionize multiple industries and drive major advancements in various fields.

Source: https://builtin.com/hardware/quantum-computing-applications

Quantum computing use cases are getting real—what you need to know

Quantum computing is rapidly advancing towards commercial viability, with recent breakthroughs and advancements in the field. For example, a research center in Japan has made progress in entangling qubits, which could improve error correction in quantum systems. Additionally, an Australian company has developed software that enhances the performance of quantum computing hardware. Major technology companies like Alibaba, Amazon, IBM, Google, and Microsoft have also launched commercial quantum-computing cloud services.

While quantum computing offers capabilities beyond conventional high-performance computers, its use cases are still largely experimental and hypothetical. Nevertheless, the increasing activity in the field indicates that leaders and chief information officers need to start formulating their quantum-computing strategies. Industries like pharmaceuticals, which can benefit from commercial quantum computing, should especially focus on planning for the future. Some companies predict the launch of usable quantum systems by 2030.

Funding for quantum computing primarily comes from public sources, but private funding is rapidly increasing. Investments in quantum-computing start-ups have surpassed $1.7 billion in 2021 alone. Hardware remains a significant bottleneck in the quantum-computing ecosystem, with challenges related to scaling the number of qubits and achieving sufficient qubit quality. The achievement of fully error-corrected, fault-tolerant quantum computing is a crucial milestone for the industry.

Software-focused start-ups in the quantum-computing industry are increasing rapidly, and larger industry participants often provide their software-development kits free of charge to build communities of developers. Cloud-based quantum-computing services may become the most valuable part of the ecosystem, offering users access to quantum computers for experimentation. Quantum computing has potential use cases in various industries, including pharmaceuticals, chemicals, automotive, and finance. The estimated value at stake in these industries ranges from $300 billion to $700 billion.

In the pharmaceutical industry, quantum computing could revolutionize research and development, speeding up the discovery and production of drugs. In chemicals, it could improve catalyst designs, resulting in energy savings and more sustainable feedstock. The automotive industry could leverage quantum computing in various areas, such as R&D, supply-chain management, and production optimization. In finance, quantum computing could enhance portfolio and risk management.

To prepare for the maturation of quantum computing, leaders in every industry should stay alert and take five concrete steps: build awareness, evaluate potential use cases, engage with the ecosystem, start investing in talent, and plan for a hybrid operating model until quantum computing becomes fully fault tolerant. Factors like funding, accessibility, standardization, industry consortia, talent, and digital infrastructure will shape the path to commercialization for quantum computing.

The potential strategic insights and business value from quantum computing make it an opportunity that leaders should not ignore. The article concludes with acknowledgments to various experts who contributed to the research.

Source: https://www.mckinsey.com/capabilities/mckinsey-digital/our-insights/quantum-computing-use-cases-are-getting-real-what-you-need-to-know

What quantum computers can do?

Quantum computers are fascinating devices that operate based on the principles of quantum mechanics. To understand their functionality, let’s imagine a simplified game involving shells and hidden objects. This analogy will help us grasp the essence of quantum computing without diving into complex physics or mathematics.

In this game, we start with 1,000 shells called qubits, which represent the basic units of information in quantum computing. Each qubit can hold either a pea or a cashew. Initially, we have 360 qubits, and a magician randomly assigns a pea or cashew to each shell with a 50% probability. The magician then writes four colored numbers, denoted as {R, G, B, W}, inside each of the 360 shells. All four numbers are equal to 1/2.

The remaining 640 shells are occupied by cashews, and inside each of them, the colored numbers are set as {R, G, B, W}={0,0,1,0}. These colored numbers represent probabilities. Specifically, the probability of finding a pea is the sum of the squares of R and G, while the probability of finding a cashew is the sum of the squares of B and W.

Now, let’s discuss the rules of the game. As a quantum programmer, you can make three specific moves without ever looking inside any shell. The goal is to choose these moves strategically so that when you eventually open all the shells, you obtain the desired answer.

The first move is called the double tap. You tap one shell with your left hand and another shell with your right hand. If the left-hand shell contains a pea, the right-hand shell will flip from cashew to pea, and vice versa. Again, you cannot observe the contents of the shells before, during, or after this move.

The second move is a color number swap. You choose a shell and select either the pair of numbers {R, G} or {B, W}. Let’s call this choice {a, b}. You replace {a, b} with new values. This move does not require any further operations since it does not affect the probabilities.

The third move is a probability fiddle. You point to a shell, and the magician waves the wand, resulting in new colored numbers:
{

}. The magician then waves the wand again and replaces the pea or cashew with the ensuing probability. It’s important to note that this move specifically requires the execution of quantum systems.

These are the three permissible moves in the game, and the order and choices you make with these moves determine the outcome. If you cannot find the correct answer within a predetermined number of attempts, the house (quantum) wins. However, if you succeed in finding the desired answer, you win. There are mathematical proofs that demonstrate the ability to solve certain important mathematical problems with a very high probability of success. This makes quantum computing a unique game where you are almost guaranteed to beat the house.

Although the rules may seem simple, a lot is happening beneath the surface. For instance, executing move 3, a total of 1,000 times, can generate an enormous number of different outcome lists. Classically, listing and optimizing all possible combinations of peas and cashews, even for 360 moves, would require printing out one 360-bit combination, one billion times a second, using every atom in the universe from the beginning of time. Quantum computers, however, can optimize over lists that surpass classical capabilities. This astounding ability raises intriguing questions for philosophers and generates a great deal of excitement.

It’s worth mentioning that the game description encompasses the universal quantum gate set, including controlled-not and Hadamard gates. The colored markings represent the real and imaginary entries of the unitary qubit operator. Although certain aspects, such as measurement iteration and convergence rate, are omitted, this description adequately captures the essence of quantum computing. Understanding the game itself is sufficient to grasp the fundamentals of quantum computing, without requiring in-depth knowledge of all the technical details and nuances.

Source: https://www.quora.com/What-quantum-computers-can-do