Quantum computing has long been the stuff of science fiction, but today it is a rapidly developing field that has attracted billions of dollars in investment from major technology companies like Google, IBM, and a host of well-funded startups. Despite the technology being years away from practical use, the potential of quantum computers to revolutionize industries from chemistry to machine learning has experts and investors alike convinced that it’s a game-changer.

The concept of building a computer based on the principles of quantum mechanics has been around since the 1980s. However, it’s only in the last few decades that scientists have made significant strides in developing large-scale quantum devices. Now, major tech players are investing heavily to accelerate the development of quantum computing.

In theory, quantum computers could solve problems that are beyond the reach of even the most powerful classical computers. From simulating complex molecular structures to optimizing large systems, quantum computing holds the promise of solving problems that current technology cannot. But experts agree that quantum machines must grow much larger and more reliable before these capabilities can be fully realized.

Once quantum computing matures, it could unlock breakthroughs across multiple fields, including chemistry, physics, materials science, and machine learning. “It’s not just a faster classical computer; this is a completely different paradigm,” says Norbert Lütkenhaus, executive director of the Institute for Quantum Computing at the University of Waterloo. “Quantum computers can solve tasks efficiently that classical computers simply cannot do.”

At the heart of any quantum computer is the qubit, the quantum analog of a classical bit. Unlike a classical bit, which can only represent a 0 or a 1, a qubit can exist in a state of superposition, where it can represent both 0 and 1 simultaneously. This ability to be in multiple states at once gives quantum computers their extraordinary computational power.

Today’s quantum computers have made impressive strides, with some machines now boasting over 1,000 qubits. However, most quantum systems in use today feature only a few dozen or a few hundred qubits, and they remain highly error-prone. The reason? Quantum states are extremely sensitive to their environment, meaning that even minor disturbances — such as fluctuations in temperature or stray electromagnetic fields — can cause errors. As a result, current quantum machines struggle to run long, complex programs capable of solving practical problems.

Despite these challenges, researchers believe that today’s quantum machines are valuable for advancing the field. “What quantum computers are used for today is essentially to learn how to build better quantum computers,” says William Oliver, director of the Center for Quantum Engineering at MIT. “They are also testing quantum algorithms and error-correction techniques, which are essential for scaling up the technology.”

One breakthrough that offers hope for future quantum systems is the development of logical qubits. By encoding quantum information across multiple physical qubits, researchers can create a more reliable and fault-tolerant unit of quantum information. Companies like Google and startups such as Quantinuum and QuEra are already demonstrating the ability to generate logical qubits. While scaling up to thousands — or even millions — of qubits will require years of work and innovation, the potential is clear.

The key to quantum computing’s power lies in the principle of superposition. This quantum phenomenon allows quantum computers to perform complex calculations in parallel. In a traditional computer, solving a problem involves checking each possible solution one by one, whereas a quantum computer can explore all possibilities simultaneously.

“As we run a quantum algorithm, incorrect solutions are suppressed, and correct solutions are enhanced,” explains Oliver. “By the end of the process, the only surviving answer is the one we’re looking for.” This ability to solve problems in parallel gives quantum computers an edge over classical systems, especially for tasks that involve large amounts of data or complex systems.

In particular, one of the most promising applications for quantum computing is simulating physical systems. The natural world itself is governed by the strange laws of quantum mechanics, and simulating quantum systems on classical computers has proven nearly impossible. But because quantum computers operate under the same principles as the systems they aim to model, they are uniquely suited to simulating complex chemical reactions, material properties, and more.

This could lead to breakthroughs in fields like drug discovery, renewable energy, and materials science. For instance, quantum computers could simulate the behavior of molecules with extreme precision, potentially revolutionizing the development of new pharmaceuticals, catalysts, or battery technologies.

However, there are also darker sides to the quantum revolution. One of the major risks posed by quantum computing is its ability to break modern encryption algorithms. Shor’s algorithm, developed in 1994, demonstrated that a sufficiently powerful quantum computer could factor large numbers exponentially faster than classical computers, potentially rendering current cryptographic systems obsolete.

Despite these concerns, the advent of quantum computing has spurred the development of new encryption techniques designed to be secure against quantum attacks. The US National Institute of Standards and Technology (NIST) has already released new encryption standards for the post-quantum era, and organizations around the world are beginning to implement these strategies to safeguard data from future quantum threats.

While today’s quantum computers are still in their infancy, the promise of the technology is undeniable. As companies continue to invest in developing larger, more stable quantum systems, we are likely to see more breakthroughs in the coming years. Achieving fault-tolerant quantum computing will require overcoming significant engineering and scientific challenges, but the potential applications — from simulating complex molecules to revolutionizing cybersecurity — are worth the effort.

For now, the quantum race continues, with billions of dollars in funding and years of research ahead. But one thing is clear: the quantum future is coming, and it could change everything.

By Impact Lab