For World Quantum Day, on the 100th anniversary of the discovery of quantum mechanics, we’re looking at how quantum computers could one day solve problems that are otherwise impossible.

This year marks a century since the discovery of quantum mechanics. That breakthrough helped people understand that the laws of physics that govern the world around us at its smallest level — molecules, atoms and subatomic particles — are fundamentally different from the laws governing the way we interact with objects in our everyday lives. Quantum mechanics has allowed us to understand the details of everything from the metabolic processes in our bloodstreams to the electric batteries powering our cars and computers, and for discoveries from lasers to semiconductors.

Quantum mechanics transformed the way we understand the natural world, and yet it wasn’t until 1981 that renowned physicist Richard Feynman observed that since the world is quantum, if we really wanted a computer to efficiently simulate all of the natural world, humanity would probably have to build a quantum computer.

Over more than a decade of scientific advances, Google has made considerable progress toward our vision of building large-scale, error-corrected quantum computers that can solve otherwise impossible problems. In celebration of World Quantum Day, let’s explore three areas where quantum computers could improve lives.

1. Better medicine

Researchers still have a lot to learn about the human body’s complex biological systems, and quantum computers may help us get a deeper understanding — like helping to understand key systems that relate to drug design and our metabolism. By calculating how certain drug candidates will interact with their targets and other biological molecules, quantum computers may help us design more effective treatments and advance medicine. As one example, in collaboration with pharma company Boehringer Ingelheim, we’ve shown that quantum computers will be able to simulate a key structure of Cytochrome P450, an enzyme found in humans, with higher accuracy in less time than classical computers. Cytochrome P450 is a critical enzyme for determining drug effectiveness, because it breaks down drugs in our bloodstream.

2. Better batteries

The world’s need for energy — and the ability to store it — is growing each year. We're investigating the way quantum computers will be able to help design new materials. For example, we’ve explored, in collaboration with chemical company BASF, that quantum computers will be able to accurately simulate Lithium Nickel Oxide (LNO), a material used in batteries. LNO is hard to produce industrially and aspects of its chemistry are not well understood, but it offers a smaller environmental footprint than commonly used lithium cobalt oxide, and we’ve even explored alternatives to the use of cobalt in batteries. Simulating the quantum mechanical behavior of LNO could improve the industrial production process, and ultimately, help us make better batteries.

3. New energy sources

Fusion energy, the power source of stars, offers the promise of clean and abundant energy — but it has yet to be realized at scale. Designing the necessary reactors relies on computational models to understand materials under extreme fusion conditions. However, current models lack accuracy, often failing to match real-world results, and demand billions of CPU hours. In collaboration with Sandia National Laboratories, our researchers showed that a quantum algorithm run on a fault-tolerant quantum computer could more efficiently simulate the mechanisms needed for sustained fusion reactions, which could ultimately help make fusion energy a reality.

This sort of progress in medicine and energy would be a big leap, and yet it may only scratch the surface of what could be possible with quantum computing. Given the complexity of this technology, it could solve questions we don’t even yet know how to ask. But realizing the full potential of quantum computing requires progress across the entire stack, including building and scaling better qubits; improving quantum error correction; developing new quantum algorithms and applying them to the real world. No one can do this alone, so we’ll continue working with partners in academia, industry and the public sector to create the most advanced quantum computing system in the world.