In the last years, a lot of brain power has been invested by researchers all around the world in the development of quantum computers, machines so powerful they could replace data centers and solve in seconds problems that would take traditional computers millennia to crack. Major tech companies and top Universities are looking at quantum computers as the next big breakthrough in computing.
The future of computation. Understanding qubits
Quantum computers are spooky devices that don’t follow the normal rules of physics. The basic units of information in a quantum processor are called qubits, or quantum bits. A qubit is a two-state quantum-mechanical system. In a classical system, a bit would have to be in one state or the other. However, quantum mechanics allows the qubit to be in a superposition of both states at the same time, a property that is fundamental to quantum computing. They can also influence one another even when they’re not physically connected, via a process known as entanglement.
The more qubits a processor has, the more information it can process instantaneously, and the more powerful it is overall. In theory, quantum computers have the advantage that they can easily solve certain mathematical problems, such as factorization of large numbers, which are very hard or even impossible for classical machines. This is possible thanks to qubit’s ability to remain, through the peculiarities of quantum mechanics, in many quantum states simultaneously. Finance, medicine, chemistry and artificial intelligence are thus all expected to be transformed by quantum computing.
The race to quantum supremacy. Recent breakthroughs
Tech giants like Intel, Google, Microsoft, IBM, Baidu are racing to become the first to achieve quantum supremacy. More recently, various startups and academic labs have gotten in the game. Quantum supremacy is the point where a quantum computer can run certain algorithms faster than a classical computer ever could. For some, this might seem like a wild goose chase, but Goldman Sachs predicts that the race to build a quantum computer will create a global industry worth $37 billion by 2021.
Recent breakthroughs are showing how close we are to creating a quantum computer that can be used to solve real-world problems.
Australian scientists led by Michelle Simmons have made a significant step in creating a world-beating, single-atom quantum computer. On the 8th of March, Simmons and her Australian team announced they had built quantum bits, known as qubits, from single phosphorus atoms in silicon that could communicate and correlate with each other. While other qubits have previously been entangled, it has never successfully been demonstrated in silicon with single atoms, both of which provide a much higher accuracy and reliability.
At the end of the last year, IBM upped their game by announcing the development of a quantum computer capable of handling 50 qubits (quantum bits). A 50-qubit machine was, at the time, the largest and most powerful quantum computer ever built.
Recently, Google crushed IBM’s record by unveiling Bristlecone, a 72-qubit gate-based superconducting system. Google said that it believes that Bristlecone will put it on a path to reach quantum supremacy in the future. The purpose of Bristlecone is to provide its researchers with a testbed “for research into system error rates and scalability of our qubit technology, as well as applications in quantum simulation, optimization, and machine learning.” Some say that Google’s Bristlecone paves the way for quantum computing to go mainstream.
Earlier this month, Alibaba launched an 11 qubit quantum computer with cloud computing access. Users can now access the superconducting quantum computing cloud through Alibaba Cloud’s quantum computing cloud platform to efficiently run and test custom built quantum codes and download the results. Dr. Shi Yaoyun, Chief Quantum Technology Scientist at Alibaba Cloud, said: “By introducing quantum computing services on cloud, we make it easier for the teams to experiment with quantum applications in a real environment to better understand the property and performance of the hardware, as well as leading the way in developing quantum tools and software globally. The user experience offered on cloud will without doubt help us further enhance our platform.”
The road to quantum computing is bumpy
Although recent developments are bringing us closer and closer to the future, there are a few problems researchers face.
One of the major issues that all quantum computers have to contend with is error rates. The qubits in quantum processors aren’t really single qubits but often a combination of numerous bits to help account for potential errors. Google’s blog post didn’t state Bristlecone’s error rate, but the company has made it clear that it strives to improve upon its previous results. Google’s best has been 0.6 percent using its much smaller 9-qubit hardware.
Quantum computers need to keep their processors extremely cold (close to absolute zero) and protect them from external shocks. Today’s Quantum bits are highly unstable and any noise can lead to errors.
Another limited factor right now is that most of these systems can only preserve their state for under 100 microseconds.
Today, the important question isn’t whether or not quantum computers will change things, but how long we have before it happens.