Taking The Quantum Computing Leap
Computing has advanced so much that we take it for granted. The power of yesteryear’s supercomputers is packed into today’s smart watches and cloud services deliver petaflops on demand. Meanwhile, the high end continues its relentless march toward the first of three exascale computers (capable of one quintillion floating-point operations per second), to be deployed by the U.S. Department of Energy (DOE) beginning in 2021 for scientific and national security research.
As exciting as these developments are, the real buzz in computing is around quantum. This new kind of computing could revolutionize scientific discovery and advance technologies from clean energy to precision medicine. Imagine being able to solve problems in seconds that would take centuries on an exascale computer. This is the promise of quantum.
No one individual or even a single institution will achieve the quantum quest. It will take a team of experts, drawing on a range of capabilities, to realize the promise of quantum computing
To work this magic, quantum computers take a radically different approach to processing information. In classical computers, information is represented by a sequence of bits that are either zero or one at any instant. In a quantum computer, information is represented by a series of qubits that can be zero and one at the same time–a concept known as superposition of quantum states. This means that a series of qubits can represent an exponentially large number of possible states that can be manipulated simultaneously. One does not know which state the computer is in until the qubits are inspected—akin to determining the fate of Schrödinger’sc at by opening its box.
Although promising, quantum computing is perplexing. Its potential impacts and the path – or paths – to realize them are being debated. Which problems are best suited to quantum computers? Can a reliable quantum computer be built? Scientists at the Department of Energy’s national laboratories, working with colleagues in academia and industry, are addressing these fundamental questions and more.
Problems such as determining the electronic structure of molecules are of particular interest because they are so difficult to solve on classical computers that one must typically settle for inadequate approximations for the most challenging problems. With a quantum computer, these same problems would be a snap.
For example, quantum computing offers unprecedented accuracy in calculating the molecular properties and behaviors of materials and the chemical reactions that take place in batteries. With this degree of precision, we will be able to design new materials that make batteries perform better, last longer, recharge faster and cost less. A quantum computer also could be used to computationally sort through millions of potential new drugs to find the one that cures your cancer, opening the door to personalized medicine.
Given the opportunities presented by quantum computing, it is no surprise that researchers around the world have joined the race to build such a machine. Although progress has been made, including some commercial offerings, a general-purpose machine of consequence is still years away. Given our decades of building supercomputers, why is this the case?.
Recall that the power of a quantum computer depends upon its ability to simultaneously represent an exponentially large number of states with a given number of qubits. Unfortunately, to deliver this power, one must be able to maintain coherence, that is, retain this exponentially large number of states for a sufficiently long time. This is extremely difficult and presents one of the greatest challenges to making a quantum computer.
Researchers are developing new materials to address this challenge and improve the reliability of quantum computers. As new materials are created, extremely powerful microscopes are used to examine their atomic structures to determine whether they meet stringent design requirements. With the help of quantum computing, it also will be possible to simulate materials with even greater precision, which could lead to even more powerful quantum computers.
No one individual or even a single institution will achieve the quantum quest. It will take a team of experts, drawing on a range of capabilities, to realize the promise of quantum computing. Toward this end, the DOE is encouraging public-private partnerships involving the national labs, leading research universities and major computing companies.
One such example is the Northwest Quantum Nexus, formed by the Pacific Northwest National Laboratory, the University of Washington and Microsoft Quantum. At this group’s inaugural summit in Seattle this spring, people from across the Northwest met to explore how best to leverage the region’s collective strengths to advance quantum computing research and development.
The Northwest Quantum Nexus also is focused on developing the quantum workforce—those who will design the materials, devices and architectures for quantum computers, as well as do the programming, develop the applications and ultimately deliver the capability of quantum computing to a wide range of industries. These people, especially the young, will change the world
Personally, I am excited to witness this enthusiasm. Years from now, when we look back on the early days of quantum computing, I am confident that we will take pride in knowing we were a part of it. Until then, we have a lot of work to do!