The most powerful quantum processor ever created is called Majorana One, and it was designed and built by Microsoft. Thanks to quantum computing, this processor could potentially reach computational power far surpassing that of all the computers on Earth today. This could bring us significantly closer to solving major challenges such as climate change, the development of new materials, new medicines, and many other pressing issues, all thanks to quantum mechanics and a new state of matter called "topological state." Microsoft has designed this chip to be much more efficient, scalable, and immune to errors, a common issue in quantum computers.
But how does a quantum computer actually work? Why is it so much more powerful than traditional computers? And why do these machines still make so many errors? Finally, did Microsoft really manage to invent something that could, in the future, enable us to achieve computational levels capable of solving incredibly complex problems like climate change, material innovation, or the development of groundbreaking medicines?
Let’s break it down. Our world can be understood through three main scientific frameworks. The classical world, which is governed by classical mechanics and includes our everyday experiences. Then there’s the relativistic world, governed by the theory of relativity, which helps us understand the behavior of massive objects like black holes or objects moving at speeds close to the speed of light. Finally, we have the quantum world, which deals with the atomic and subatomic scales, where classical mechanics doesn't apply. Quantum mechanics is the branch of physics that studies phenomena at this tiny scale.
However, the worlds of relativity and quantum mechanics are counterintuitive because we don’t experience them directly in our everyday lives. For example, in the movie Interstellar, when Cooper returns to meet his daughter, he finds she’s much older than him due to time dilation. This is a direct consequence of relativity, which, while strange, is a real phenomenon. In our daily experience, time dilation is hardly noticeable due to the relatively small gravitational effects we encounter on Earth compared to those near black holes or at speeds near the speed of light.
Now, let’s talk about quantum mechanics, which may seem even more confusing. For a basic understanding of quantum computing, we need to grasp two essential concepts: superposition and qubits.
First, superposition. Imagine tossing a coin. Before you look at it, it could be either heads or tails, but quantum mechanics tells us that, until we observe it, it’s simultaneously both heads and tails. In quantum mechanics, a system can exist in a superposition of multiple states at the same time, but once we measure it, the system collapses into one of those states. For example, a quantum system could be in a superposition of being both 0 and 1 at the same time, unlike a classical bit, which can only be either 0 or 1.
This idea leads us to the concept of qubits (quantum bits), which are the basic units of information in quantum computers. A qubit is not restricted to being 0 or 1 like a classical bit. Instead, it can represent both 0 and 1 simultaneously, along with all possible combinations in between, thanks to superposition. This ability allows quantum computers to perform computations in parallel, analyzing multiple possibilities at the same time. This is a key advantage over classical computers, which can only process one possibility at a time.
However, there’s a challenge: quantum systems are incredibly fragile. Any interaction with the outside world can cause a quantum system to lose its superposition and collapse into a specific state, which introduces errors. For a quantum computer to work efficiently, it needs to be kept in extremely controlled environments, often at near absolute zero temperatures, to reduce these interactions and errors.
So, how do quantum computers process information so much faster than classical ones? Let’s say you have three bits in a classical computer. These bits can be arranged in eight different combinations, but the computer processes only one combination at a time. A quantum computer, on the other hand, with three qubits, can handle all eight combinations simultaneously due to superposition. This means quantum computers can solve certain complex problems much faster by processing multiple possibilities in parallel.
But there’s a crucial issue in quantum computing: errors. The extremely delicate nature of quantum states makes them prone to errors, especially when interacting with their environment. This is where Microsoft’s breakthrough with Majorana One comes in. The key innovation lies in the creation of topological qubits. These qubits are made possible by a special state of matter known as the topological state, which is much more resistant to external disturbances. This is because the quantum information in topological qubits is stored in the geometry of the material itself, making it less susceptible to errors caused by noise.
The material used to create these topological qubits is a combination of indium arsenide and aluminum, carefully assembled at the atomic level. This creates a situation where special particles called Majorana fermions can emerge. These fermions are unique in that they are their own antiparticles. Although Majorana fermions have not yet been observed in nature, their quasi-particles (particles with similar properties) can be created in certain superconducting materials, like those used by Microsoft.
These topological qubits are much more robust than traditional qubits. Because the quantum information is stored in the topological properties of the material, it is more immune to disturbances from the outside world. The concept behind this is called braiding. In this process, Majorana fermions, which are paired together, can be braided (moved around) in specific ways to perform quantum operations. This braiding reduces the likelihood of errors because it doesn’t involve directly interacting with the qubits, which would otherwise disturb their state.
Microsoft’s Majorana One chip is still in its early stages, with only eight qubits currently in use, but the potential for scaling up is enormous. Microsoft’s goal is to create a chip that can handle a million qubits, making it capable of solving real-world problems that are currently out of reach for even the most advanced classical computers and supercomputers. If successful, such a chip would have computational power far exceeding all the computers in the world combined, enabling us to solve complex problems in fields like material science, medicine, and climate change.
While it’s still early days, the promise of quantum computing, especially with innovations like Majorana One, could revolutionize industries and accelerate the solutions to some of humanity's most pressing challenges.