The concept of quantum computing has been around for decades. A traditional computer stores data in the form of bits, which can be in one of two definite states at any given time. A quantum computer stores data in the form of qubits, which can be in a superposition of states. In other words, somewhere in between.
This property of qubits creates the potential for a quantum computer to solve problems that can't be practically solved with a traditional computer, or to vastly speed up certain types of computations. While this technology is likely many years away from meaningful commercialization, a handful of tech companies are charging ahead.
Alphabet's (NASDAQ:GOOG) Google is one of them. Google presented its new 72-qubit Bristlecone quantum processor on Monday at the American Physical Society meeting. The company plans to use Bristlecone as a test bed for further research into error rates and scalability of quantum systems. Google also will use the chip for applications in quantum simulation, optimization, and machine learning.
One of the biggest challenges to building a useful quantum computer is dealing with errors. Traditional computers can use redundancy to correct errors. Error correction in quantum computers, with qubits in fuzzy combinations of states, is more complicated.
Google is "cautiously optimistic" that Bristlecone eventually will achieve quantum supremacy, meaning that the processor would be able to solve a problem that can't be practically solved by a traditional computer. The company believes getting the 2-qubit error rate below 0.5% is the threshold for this achievement. With its earlier 9-qubit linear array technology, Google got that error rate down to 0.6%.
Not the only game in town
Google's 72-qubit system comes a few months after International Business Machines (NYSE:IBM) unveiled its own prototype 50-qubit quantum computer. Along with that news, IBM announced partnerships with 12 organizations, including JPMorgan Chase, Samsung, and Barclays. Each have plans to test out IBM's quantum systems for solving real-world problems. JPMorgan Chase, for example, will use the system for trading strategies, portfolio optimization, asset pricing, and risk management.
Other companies working on quantum computing include Microsoft (NASDAQ:MSFT) and Intel (NASDAQ:INTC). Microsoft is working on building its own quantum computer using topological qubits that could make reducing the error rate an easier task. Microsoft also released a brand-new domain-specific programming language called Q#, for expressing quantum algorithms. That code can be run on a quantum simulator powered by the company's Azure cloud platform.
Intel unveiled a 49-qubit quantum-computing chip called Tangle Lake earlier this year, which came two months after the company delivered a 17-qubit quantum chip to a research partner. Intel doesn't expect meaningful commercialization to occur in the near term. Mike Mayberry, managing director of Intel Labs, sees a long road ahead: "We expect it will be five to seven years before the industry gets to tackling engineering-scale problems, and it will likely require 1 million or more qubits to achieve commercial relevance."
A marathon, not a sprint
Google's Bristlecone is another step forward for quantum computing. Beating a supercomputer is the next big challenge, and Google thinks it will be a critical achievement in the path to commercialization. "We believe the experimental demonstration of a quantum processor outperforming a supercomputer would be a watershed moment for our field, and remains one of our key objectives," reads Google's blog post announcing Bristlecone.
While it may seem like progress is coming quickly, it could take many years, or even decades, before quantum computing is useful in the real world. The race is wide open at this point, and there's no telling which companies will ultimately prevail.