Quantum computing may still be in the early stages of evolution, but its potential impact on everyday life is significant. We delve into the key concepts behind it, the reasons for its rapid growth, and how global advancements are shaping its future.
Imagine you’re searching for a specific book on Amazon, a platform with millions of titles. Now, let’s assume you’re using a powerful computer with an Intel i7 processor running at around 5GHz. In this scenario, the i7 processor isn’t just running the Amazon website on your device, but also assumed to be searching through Amazon’s massive database of millions of books. While the Intel i7 is fast for many tasks, searching such a large database with just this processor would still take considerable time. Even with multiple cores, each core can handle only one part of the search at a time, which means the process could take several minutes, especially when checking millions of records. Today, however, systems like Amazon’s can return results in seconds, thanks to advanced algorithms, distributed systems, and parallel processing across many servers—not just the power of a single i7 processor.
Let’s explore another amazing feature beyond individual computing: distributed computing. This technique drives most modern computing systems. In distributed computing, multiple processors or cores in a network of computers work together to solve a problem faster. For example, Amazon’s search engine leverages this technology when you search for a product. Behind the scenes, Amazon’s system operates on a distributed network of hundreds of powerful servers, each equipped with multiple processors. When you search for an item, the search request is split into many parts, and different servers handle different sections of the search simultaneously, dramatically speeding up the process. This allows Amazon to quickly scan through millions of product listings and return relevant results in just a few seconds. However, even with such advanced distributed computing, each server and processor still works step by step through its assigned data. While multiple servers may handle different sections of the search query at the same time, each server processes its own chunk of data one piece at a time.
While distributed computing can accelerate searches, even the most powerful systems face limitations when it comes to processing vast amounts of data, especially as databases continue to grow exponentially. This is where new computing methods, such as quantum computing, are poised to bring about a transformative difference. Instead of processing tasks sequentially, a quantum computer can evaluate all possible solutions at once. This capability comes from a key concept in quantum mechanics known as superposition. So, instead of checking each result one by one or relying on distributed computing, a quantum computer can examine all possibilities simultaneously, delivering the solution much faster.
Let’s revisit the Amazon search example. Currently, Amazon doesn’t use quantum computing; instead, it relies on highly optimised classical computing systems with distributed computing to quickly sort through millions of titles and return relevant results. But imagine if Amazon were to adopt quantum computing in the future. With a quantum computer, all possibilities could be evaluated at the same time, drastically reducing the time required. What might take minutes or even hours on a traditional system could potentially be completed in seconds with quantum technology.
This potential isn’t just theoretical—it holds immense real-world implications. For instance, when you search for information on Google, classical computers use sophisticated algorithms and distributed processing to evaluate and rank results. With quantum computing, however, such systems could analyse all possible results at once, potentially returning the most relevant answers in a fraction of a second, transforming the speed and accuracy of search as we know it.
The qubit advantage
Quantum computing represents a fundamental shift from traditional computing. While classical computers process data using bits, which are either 0 or 1, quantum computers rely on qubits. A qubit, or quantum bit, is unique because it can exist in both 0 and 1 states simultaneously, thanks to a phenomenon known as superposition. This superposition means that each qubit added doubles the number of possible states. For example, with a single qubit, there are only two possible states: 0 or 1. However, with two qubits, there are four possible states: 00, 01, 10, and 11. By the time we reach three qubits, the states increase to eight combinations (000, 001, 010, 011, 100, 101, 110, and 111). In general, n qubits can represent 2n states. Therefore, four qubits can represent 16 different states simultaneously, and adding even one more qubit doubles this to 32 states. This exponential growth provides quantum computers with an unprecedented level of computational capacity, enabling them to tackle complex problems that are beyond the reach of classical systems.
Looking towards the future, as quantum computing progresses, we could see systems with hundreds or even thousands of qubits, potentially reaching a power far beyond today’s classical systems. For instance, a quantum computer with 100 qubits could represent 2100 states, an astronomically large number, enabling it to solve problems that would be impossible for classical computers, even with millions of processors.
However, qubits are highly sensitive and can be disrupted by environmental factors such as heat, electromagnetic radiation, or even slight vibrations. These disturbances cause ‘quantum decoherence’ where the qubit loses its quantum state and the system collapses into classical behaviour. To prevent this, quantum computers typically operate at extremely low temperatures, close to absolute zero, to minimise thermal fluctuations. Specialised cooling techniques, like dilution refrigerators, are used to lower the temperature of qubits to just a fraction of a degree above absolute zero. Additionally, the materials and design of the quantum processor must be carefully engineered to shield qubits from external noise.
Superposition
In classical computing, a byte (which is made up of 8 bits) can store values like 1, 0, or even a combination like 10101100. But a qubit works differently. It can represent 0, 1, or both 0 and 1 at the same time until it is measured. You could think of it as having a value of 0.5 for 0 and 0.5 for 1, meaning there is an equal chance of it being 0 or 1 when checked, instead of just being one or the other. This ability of qubits to exist in multiple states simultaneously is what gives quantum computers their power. While a regular computer must process each possibility one by one, a quantum computer can process many possibilities at once.
Imagine you’re looking for a specific movie on a streaming platform like Netflix. In traditional computing, a classical computer would need to go through the list of movies one by one, checking each to see if it matches your search. With a quantum computer using superposition, you can look at the entire library of movies at once, all in parallel. Instead of checking each movie one by one, a quantum computer can process all possible matches at the same time. This means that you can find the movie you are searching for in a fraction of a second, instead of waiting minutes or even hours to scroll through the results.
Here is another example. Let’s say you’re looking for a particular product on Amazon, but there are millions of items in the store. A classical computer would search through the items one by one, or at best, in parallel chunks, but still check each item sequentially. A quantum computer can search through all the millions of items simultaneously, thanks to superposition. It can look at the entire database of products at once, instantly evaluating which ones match your search, without having to go step by step.
This ability to evaluate multiple possibilities at the same time makes quantum computers vastly more efficient for certain tasks, especially when there are lots of potential outcomes, like searching through massive databases or solving complex problems.
Entanglement
Another important feature of quantum computing is entanglement. Quantum entanglement occurs when two qubits become linked together in such a way that the state of one qubit directly affects the state of the other, even when they are far apart. In other words, once two qubits are entangled, measuring the state of one qubit (whether it’s 0 or 1) immediately reveals the state of the other qubit, regardless of the distance between them. This phenomenon is what makes quantum computers so powerful, as it allows them to perform complex calculations much faster than traditional computers.
In classical computing, each operation is processed step by step, one at a time. However, with quantum entanglement, quantum computers can process linked qubits simultaneously. This means that instead of handling one calculation at a time, quantum computers can solve multiple calculations at once, greatly speeding up the process, especially for problems that involve large amounts of data or need complex processing. For example, imagine two satellites orbiting the Earth — one above India and the other above Brazil. If these satellites were using quantum entanglement for communication, any change or measurement of data from one satellite could instantly affect the data received by the other, even though they are thousands of kilometres apart. Unlike traditional communication, which relies on signals travelling through space at the speed of light, quantum entanglement works differently. In entanglement, the data from one satellite is linked to the other in such a way that when you measure one, you instantly know the state of the other, no matter the distance between them. This connection doesn’t require signals to physically travel through space, making it much harder for anyone to intercept or interfere with the communication. The result is not only faster communication but also an ultra-secure method for transferring data. This unique feature of quantum communication allows it to solve certain problems much more efficiently and securely than traditional methods.
Quantum entanglement could play a critical role in the development of ultra-secure communications. Due to the unique behaviour of entangled qubits, any attempt to intercept information being transmitted between them would be immediately noticed. This makes quantum communication nearly impossible to hack. If an intruder tries to interfere with the data, it will disturb the quantum state, alerting the parties involved. This level of security is especially valuable for sensitive communications, such as those in government, banking, or personal exchanges.
Quantum entanglement also has the potential to significantly improve cloud computing. In traditional cloud systems, servers store and process data independently. With quantum entanglement, servers could work together in real-time, sharing information and solving complex problems more efficiently. This could significantly speed up data processing for large-scale tasks, like simulations or analysing massive datasets.
Quantum entanglement has transformative potential across various industries. In cybersecurity, it can provide instant detection of any attempts to intercept or tamper with data, making hacking nearly impossible and enhancing digital transaction security. In healthcare, quantum computers could process vast amounts of biological data simultaneously, accelerating drug discovery and helping find cures for diseases like cancer. In business, quantum entanglement could optimise supply chains by synchronising data across different parts of a company in real-time, improving decision-making and reducing costs.
With these incredible properties—superposition and entanglement—quantum computers are pushing the boundaries of what’s possible in cryptography, artificial intelligence (AI), and scientific research. Quantum computing could break current encryption methods or help create stronger, more secure systems. In AI, quantum computers could enable faster, smarter algorithms, improving areas like recommendation systems, self-driving cars, or medical diagnosis.
Recognising the importance of quantum computing, the Indian government has launched the National Quantum Mission (NQM) with a planned investment of more than Rs 60 billion from 2023-24 to 2030-31.
How did it all start?
The journey of quantum computing began over a century ago, when scientists started exploring the strange behaviour of particles like electrons and photons. This study, called quantum mechanics, laid the foundation for the development of quantum computing. Key figures such as Albert Einstein, Niels Bohr, and Erwin Schrödinger helped us understand how particles can behave in ways that don’t fit with our everyday experience of physics. For example, Schrödinger created a famous thought experiment, known as ‘Schrödinger’s cat’, to explain the idea of superposition—the concept that a quantum particle can exist in multiple states at once.
In this thought experiment, Schrödinger imagined a cat inside a box with a device that has a 50% chance of releasing poison. According to quantum theory, until the box is opened and the cat is observed, the cat is both alive and dead at the same time. This strange idea helps explain superposition in quantum computing—where a qubit can be in a state of 0, 1, or both at once, which is different from a regular computer bit that can only be 0 or 1.
In the 1980s, scientists like Richard Feynman and David Deutsch began discussing how quantum mechanics could be used to build computers capable of solving problems much faster than traditional computers. They suggested that quantum computers could handle complex calculations and vast amounts of data at unimaginable speeds, potentially leading to groundbreaking advancements.
A significant breakthrough in the field of quantum computing came in 1994 when mathematician Peter Shor introduced Shor’s Algorithm. This algorithm demonstrated that quantum computers could factor large numbers exponentially faster than classical computers. Factoring large numbers means breaking them down into smaller prime numbers. For example, the number 15 can be factored into 3 and 5, which are prime numbers that multiply to give 15. However, as the numbers grow much larger—such as those used in modern encryption—it becomes incredibly difficult and time-consuming for classical computers to factor them. This process is essential for many encryption techniques that protect sensitive information online, such as credit card details and private communications.
Shor’s discovery showed that quantum computers could perform this task at a much faster rate, potentially breaking encryption methods that rely on the difficulty of factoring large numbers. This posed a significant threat to data security, as current encryption systems might become vulnerable to quantum attacks. As a result, his work sparked a global effort to advance quantum computing research and develop new encryption methods capable of resisting the power of quantum computers.
In 2019, Google claimed to have achieved quantum supremacy, where its quantum computer completed a task in 200 seconds that would take classical supercomputers 10,000 years. This milestone signalled the potential of quantum technology to revolutionise industries. However, IBM disagreed, arguing that the task could be completed in just 2.5 days using a traditional computer, and urged caution in accepting Google’s claim. Google defended its achievement, comparing it to the Wright brothers’ first flight, which showed the possibility of flight, even if it had no immediate practical use. Despite the debate, quantum computing is still evolving.
The quantum future – opportunities and challenges
Quantum computing has the potential to revolutionise many industries, from finance to healthcare, and beyond. One of its most exciting applications is in cryptography and cybersecurity. Today, we rely on encryption methods to protect our personal and financial data online. However, as quantum computers become more powerful, they could easily break these encryption systems. This is why quantum-safe encryption—methods that are secure against quantum attacks—is becoming crucial. In India, companies like QNu Labs are already developing quantum-safe encryption technologies, while global giants like IBM and Microsoft are also working on similar solutions to secure data.
In healthcare, quantum computers have the potential to change the way we develop medicines. They can simulate molecules and chemical reactions at a level of detail that classical computers simply can’t match. This ability could speed up the process of discovering new drugs. For example, biotech companies in the US are using quantum computers to simulate proteins, which may lead to breakthroughs in the treatment of diseases like cancer and Alzheimer’s.
In finance, quantum computing could make a huge difference by helping banks and investment firms solve complex problems faster and more accurately. JPMorgan Chase, in collaboration with IBM, is exploring how quantum computing could improve financial models, optimise investment portfolios, and predict risks more efficiently. In India, banks and financial institutions are following quantum developments closely, preparing for a future where quantum computing could change the way they do business—by enhancing fraud detection, improving trading algorithms, and optimising asset management.
The logistics and manufacturing industries are also set to benefit from quantum computing. Companies involved in transportation can use quantum algorithms to find the most efficient routes for their deliveries, saving fuel and reducing costs. Volkswagen, for example, has experimented with quantum computing to optimise traffic flow in cities, making transportation smoother and faster. Similarly, logistics companies in India are exploring how quantum computing can improve delivery networks, making them more efficient and cost-effective.
Another exciting area is AI. Quantum computing could take machine learning to the next level. AI systems learn from data, and quantum computers can process large datasets much faster and more efficiently than classical computers. Google is already researching how quantum computers could improve AI models for tasks like natural language processing, image recognition, and more. This could lead to smarter, faster, and more accurate AI systems in many fields.
However, quantum computing is not without its challenges. One of the most pressing issues is the high error rate in quantum systems. Quantum computers are incredibly sensitive to their surroundings; even small changes in temperature or electromagnetic interference can cause errors. Researchers are working on quantum error correction techniques, but creating stable, large-scale systems remains a complex task. Despite this, the promise of quantum computing remains strong, and we are making strides toward overcoming these obstacles.
Experts predict that it may take a decade or more before quantum computers are fully commercialised and accessible to the public. Until then, we might see hybrid systems, where quantum computers work alongside traditional computers to solve specific, computationally intensive problems.
As quantum computing progresses, it will also raise important ethical and societal questions. If quantum computers become powerful enough to break current encryption systems, our data could be at risk. To address this, quantum-safe encryption is already being researched, and countries, including India, are developing policies to ensure that we stay ahead of potential threats. Additionally, as the demand for quantum technology grows, we will see new job opportunities emerge in quantum programming, engineering, and ethical data handling.
In India, leading institutions such as the Indian Institutes of Technology (IITs) and Indian Institute of Science (IISc) are offering specialised programs to prepare students for this future. Similarly, top global universities, including MIT and Oxford, are expanding their quantum computing courses to meet the growing demand. This new wave of education presents a unique opportunity for students to become pioneers in this field.
Quantum computing has the potential to solve some of the world’s toughest problems. Although it is still in its early stages, its impact is already beginning to show, and the possibilities are endless. For youngsters, it’s a chance to be part of a technological revolution that will shape the future.
